Store null GL context's state in interface object

BUG=skia:
GOLD_TRYBOT_URL= https://gold.skia.org/search2?unt=true&query=source_type%3Dgm&master=false&issue=1814113002

Review URL: https://codereview.chromium.org/1814113002

8 files changed, 1154 insertions, 973 deletions

diff --git a/gyp/gpu.gypi b/gyp/gpu.gypi
index 49d087fba0..2b5f9cd8d3 100644
--- a/gyp/gpu.gypi
+++ b/gyp/gpu.gypi
@@ -351,6 +351,8 @@
       '<(skia_src_path)/gpu/gl/GrGLRenderTarget.h',
       '<(skia_src_path)/gpu/gl/GrGLStencilAttachment.cpp',
       '<(skia_src_path)/gpu/gl/GrGLStencilAttachment.h',
+      '<(skia_src_path)/gpu/gl/GrGLTestInterface.cpp',
+      '<(skia_src_path)/gpu/gl/GrGLTestInterface.h',
       '<(skia_src_path)/gpu/gl/GrGLTexture.cpp',
       '<(skia_src_path)/gpu/gl/GrGLTexture.h',
       '<(skia_src_path)/gpu/gl/GrGLTextureRenderTarget.cpp',
diff --git a/include/gpu/gl/GrGLFunctions.h b/include/gpu/gl/GrGLFunctions.h
index fcd89e1406..5708cce7ef 100644
--- a/include/gpu/gl/GrGLFunctions.h
+++ b/include/gpu/gl/GrGLFunctions.h
@@ -39,13 +39,12 @@ typedef GrGLenum (GR_GL_FUNCTION_TYPE* GrGLCheckFramebufferStatusProc)(GrGLenum
 typedef GrGLvoid (GR_GL_FUNCTION_TYPE* GrGLClearProc)(GrGLbitfield mask);
 typedef GrGLvoid (GR_GL_FUNCTION_TYPE* GrGLClearColorProc)(GrGLclampf red, GrGLclampf green, GrGLclampf blue, GrGLclampf alpha);
 typedef GrGLvoid (GR_GL_FUNCTION_TYPE* GrGLClearStencilProc)(GrGLint s);
-typedef GrGLvoid (GR_GL_FUNCTION_TYPE* GrGLClientActiveTextureProc)(GrGLenum texture);
 typedef GrGLvoid (GR_GL_FUNCTION_TYPE* GrGLColorMaskProc)(GrGLboolean red, GrGLboolean green, GrGLboolean blue, GrGLboolean alpha);
 typedef GrGLvoid (GR_GL_FUNCTION_TYPE* GrGLCompileShaderProc)(GrGLuint shader);
 typedef GrGLvoid (GR_GL_FUNCTION_TYPE* GrGLCompressedTexImage2DProc)(GrGLenum target, GrGLint level, GrGLenum internalformat, GrGLsizei width, GrGLsizei height, GrGLint border, GrGLsizei imageSize, const GrGLvoid* data);
 typedef GrGLvoid (GR_GL_FUNCTION_TYPE* GrGLCompressedTexSubImage2DProc)(GrGLenum target, GrGLint level, GrGLint xoffset, GrGLint yoffset, GrGLsizei width, GrGLsizei height, GrGLenum format, GrGLsizei imageSize, const GrGLvoid* data);
 typedef GrGLvoid (GR_GL_FUNCTION_TYPE* GrGLCopyTexSubImage2DProc)(GrGLenum target, GrGLint level, GrGLint xoffset, GrGLint yoffset, GrGLint x, GrGLint y, GrGLsizei width, GrGLsizei height);
-typedef GrGLuint (GR_GL_FUNCTION_TYPE* GrGLCreateProgramProc)(void);
+typedef GrGLuint (GR_GL_FUNCTION_TYPE* GrGLCreateProgramProc)();
 typedef GrGLuint (GR_GL_FUNCTION_TYPE* GrGLCreateShaderProc)(GrGLenum type);
 typedef GrGLvoid (GR_GL_FUNCTION_TYPE* GrGLCullFaceProc)(GrGLenum mode);
 typedef GrGLvoid (GR_GL_FUNCTION_TYPE* GrGLDeleteBuffersProc)(GrGLsizei n, const GrGLuint* buffers);
@@ -67,7 +66,6 @@ typedef GrGLvoid (GR_GL_FUNCTION_TYPE* GrGLDrawBuffersProc)(GrGLsizei n, const G
 typedef GrGLvoid (GR_GL_FUNCTION_TYPE* GrGLDrawElementsProc)(GrGLenum mode, GrGLsizei count, GrGLenum type, const GrGLvoid* indices);
 typedef GrGLvoid (GR_GL_FUNCTION_TYPE* GrGLDrawElementsInstancedProc)(GrGLenum mode, GrGLsizei count, GrGLenum type, const GrGLvoid *indices, GrGLsizei primcount);
 typedef GrGLvoid (GR_GL_FUNCTION_TYPE* GrGLDrawElementsIndirectProc)(GrGLenum mode, GrGLenum type, GrGLvoid* indirect);
-typedef GrGLvoid (GR_GL_FUNCTION_TYPE* GrGLEGLImageTargetTexture2DProc)(GrGLenum target, GrGLeglImage image);
 typedef GrGLvoid (GR_GL_FUNCTION_TYPE* GrGLEnableProc)(GrGLenum cap);
 typedef GrGLvoid (GR_GL_FUNCTION_TYPE* GrGLEnableVertexAttribArrayProc)(GrGLuint index);
 typedef GrGLvoid (GR_GL_FUNCTION_TYPE* GrGLEndQueryProc)(GrGLenum target);
diff --git a/include/gpu/gl/SkNullGLContext.h b/include/gpu/gl/SkNullGLContext.h
index 9e799a9fea..5a2a73fd8f 100644
--- a/include/gpu/gl/SkNullGLContext.h
+++ b/include/gpu/gl/SkNullGLContext.h
@@ -13,24 +13,14 @@
 class SK_API SkNullGLContext : public SkGLContext {
 public:
     ~SkNullGLContext() override;
-
     static SkNullGLContext* Create();
-    // FIXME: remove once Chromium has been updated.
-    static SkNullGLContext* Create(GrGLStandard forcedAPI) {
-        SkASSERT(forcedAPI == kNone_GrGLStandard);
-        (void)forcedAPI;        return Create();
-    }
-
-    class ContextState;
 
 private:
     SkNullGLContext();
 
-    void onPlatformMakeCurrent() const override;
+    void onPlatformMakeCurrent() const override {};
     void onPlatformSwapBuffers() const override {}
-    GrGLFuncPtr onPlatformGetProcAddress(const char*) const override { return NULL; }
-
-    ContextState* fState;
+    GrGLFuncPtr onPlatformGetProcAddress(const char*) const override { return nullptr; }
 };
 
 #endif
diff --git a/src/gpu/gl/GrGLCreateNullInterface.cpp b/src/gpu/gl/GrGLCreateNullInterface.cpp
index dd48bd8f0f..ccaab598b8 100644
--- a/src/gpu/gl/GrGLCreateNullInterface.cpp
+++ b/src/gpu/gl/GrGLCreateNullInterface.cpp
@@ -7,12 +7,9 @@
 
 
 #include "gl/GrGLInterface.h"
-#include "GrGLDefines.h"
+#include "GrGLTestInterface.h"
+#include "SkMutex.h"
 #include "SkTDArray.h"
-#include "GrGLNoOpInterface.h"
-#include "SkTLS.h"
-
-// TODO: Delete this file after chrome starts using SkNullGLContext.
 
 // added to suppress 'no previous prototype' warning and because this code is duplicated in
 // SkNullGLContext.cpp
@@ -20,10 +17,7 @@ namespace {
 
 class BufferObj {
 public:
-    
-
-    BufferObj(GrGLuint id) : fID(id), fDataPtr(nullptr), fSize(0), fMapped(false) {
-    }
+    BufferObj(GrGLuint id) : fID(id), fDataPtr(nullptr), fSize(0), fMapped(false) {}
     ~BufferObj() { delete[] fDataPtr; }
 
     void allocate(GrGLsizeiptr size, const GrGLchar* dataPtr) {
@@ -53,8 +47,6 @@ private:
 // This class maintains a sparsely populated array of buffer pointers.
 class BufferManager {
 public:
-    
-
     BufferManager() : fFreeListHead(kFreeListEnd) {}
 
     ~BufferManager() {
@@ -114,383 +106,509 @@ private:
     SkTDArray<BufferObj*>   fBuffers;
 };
 
-/**
- * The global-to-thread state object for the null interface. All null interfaces on the
- * same thread currently share one of these. This means two null contexts on the same thread
- * can interfere with each other. It may make sense to more integrate this into SkNullGLContext
- * and use it's makeCurrent mechanism.
- */
-struct ThreadContext {
+/** Null interface implementation */
+class NullInterface : public GrGLTestInterface {
 public:
-    
+    NullInterface()
+        : fCurrArrayBuffer(0)
+        , fCurrElementArrayBuffer(0)
+        , fCurrPixelPackBuffer(0)
+        , fCurrPixelUnpackBuffer(0)
+        , fCurrShaderID(0)
+        , fCurrGenericID(0)
+        , fCurrUniformLocation(0) {
+        this->init(kGL_GrGLStandard);
+    }
+
+    GrGLenum checkFramebufferStatus(GrGLenum target) override {
+        return GR_GL_FRAMEBUFFER_COMPLETE;
+    }
+
+    GrGLvoid genBuffers(GrGLsizei n, GrGLuint* ids) override {
+        for (int i = 0; i < n; ++i) {
+            BufferObj* buffer = fBufferManager.create();
+            ids[i] = buffer->id();
+        }
+    }
+
+    GrGLvoid bufferData(GrGLenum target, GrGLsizeiptr size, const GrGLvoid* data,
+                        GrGLenum usage) override {
+        GrGLuint id = 0;
+
+        switch (target) {
+            case GR_GL_ARRAY_BUFFER:
+                id = fCurrArrayBuffer;
+                break;
+            case GR_GL_ELEMENT_ARRAY_BUFFER:
+                id = fCurrElementArrayBuffer;
+                break;
+            case GR_GL_PIXEL_PACK_BUFFER:
+                id = fCurrPixelPackBuffer;
+                break;
+            case GR_GL_PIXEL_UNPACK_BUFFER:
+                id = fCurrPixelUnpackBuffer;
+                break;
+            default:
+                SkFAIL("Unexpected target to nullGLBufferData");
+                break;
+        }
+
+        if (id > 0) {
+            BufferObj* buffer = fBufferManager.lookUp(id);
+            buffer->allocate(size, (const GrGLchar*) data);
+        }
+    }
+
+    GrGLuint createProgram() override {
+        return ++fCurrProgramID;
+    }
+
+    GrGLuint createShader(GrGLenum type) override {
+        return ++fCurrShaderID;
+    }
+
+    GrGLvoid bindBuffer(GrGLenum target, GrGLuint buffer) override {
+        switch (target) {
+            case GR_GL_ARRAY_BUFFER:
+                fCurrArrayBuffer = buffer;
+                break;
+            case GR_GL_ELEMENT_ARRAY_BUFFER:
+                fCurrElementArrayBuffer = buffer;
+                break;
+            case GR_GL_PIXEL_PACK_BUFFER:
+                fCurrPixelPackBuffer = buffer;
+                break;
+            case GR_GL_PIXEL_UNPACK_BUFFER:
+                fCurrPixelUnpackBuffer = buffer;
+                break;
+        }
+    }
+
+   // deleting a bound buffer has the side effect of binding 0
+    GrGLvoid deleteBuffers(GrGLsizei n, const GrGLuint* ids) override {
+        for (int i = 0; i < n; ++i) {
+            if (ids[i] == fCurrArrayBuffer) {
+                fCurrArrayBuffer = 0;
+            }
+            if (ids[i] == fCurrElementArrayBuffer) {
+                fCurrElementArrayBuffer = 0;
+            }
+            if (ids[i] == fCurrPixelPackBuffer) {
+                fCurrPixelPackBuffer = 0;
+            }
+            if (ids[i] == fCurrPixelUnpackBuffer) {
+                fCurrPixelUnpackBuffer = 0;
+            }
+
+            BufferObj* buffer = fBufferManager.lookUp(ids[i]);
+            fBufferManager.free(buffer);
+        }
+    }
+
+    GrGLvoid genFramebuffers(GrGLsizei n, GrGLuint *framebuffers) override {
+        this->genGenericIds(n, framebuffers);
+    }
+
+    GrGLvoid genQueries(GrGLsizei n, GrGLuint *ids) override { this->genGenericIds(n, ids); }
+
+    GrGLvoid genRenderbuffers(GrGLsizei n, GrGLuint *renderbuffers) override {
+        this->genGenericIds(n, renderbuffers);
+    }
+
+    GrGLvoid genTextures(GrGLsizei n, GrGLuint *textures) override {
+        this->genGenericIds(n, textures);
+    }
+
+    GrGLvoid genVertexArrays(GrGLsizei n, GrGLuint *arrays) override {
+        this->genGenericIds(n, arrays);
+    }
+
+    GrGLenum getError() override { return GR_GL_NO_ERROR; }
+
+    GrGLvoid getIntegerv(GrGLenum pname, GrGLint* params) override {
+        // TODO: remove from Ganesh the #defines for gets we don't use.
+        // We would like to minimize gets overall due to performance issues
+        switch (pname) {
+            case GR_GL_CONTEXT_PROFILE_MASK:
+                *params = GR_GL_CONTEXT_COMPATIBILITY_PROFILE_BIT;
+                break;
+            case GR_GL_STENCIL_BITS:
+                *params = 8;
+                break;
+            case GR_GL_SAMPLES:
+                *params = 1;
+                break;
+            case GR_GL_FRAMEBUFFER_BINDING:
+                *params = 0;
+                break;
+            case GR_GL_VIEWPORT:
+                params[0] = 0;
+                params[1] = 0;
+                params[2] = 800;
+                params[3] = 600;
+                break;
+            case GR_GL_MAX_VERTEX_TEXTURE_IMAGE_UNITS:
+            case GR_GL_MAX_GEOMETRY_TEXTURE_IMAGE_UNITS:
+            case GR_GL_MAX_TEXTURE_IMAGE_UNITS:
+            case GR_GL_MAX_COMBINED_TEXTURE_IMAGE_UNITS:
+                *params = 8;
+                break;
+            case GR_GL_MAX_TEXTURE_COORDS:
+                *params = 8;
+                break;
+            case GR_GL_MAX_VERTEX_UNIFORM_VECTORS:
+                *params = kDefaultMaxVertexUniformVectors;
+                break;
+            case GR_GL_MAX_FRAGMENT_UNIFORM_VECTORS:
+                *params = kDefaultMaxFragmentUniformVectors;
+                break;
+            case GR_GL_MAX_FRAGMENT_UNIFORM_COMPONENTS:
+                *params = 16 * 4;
+                break;
+            case GR_GL_NUM_COMPRESSED_TEXTURE_FORMATS:
+                *params = 0;
+                break;
+            case GR_GL_COMPRESSED_TEXTURE_FORMATS:
+                break;
+            case GR_GL_MAX_TEXTURE_SIZE:
+                *params = 8192;
+                break;
+            case GR_GL_MAX_RENDERBUFFER_SIZE:
+                *params = 8192;
+                break;
+            case GR_GL_MAX_SAMPLES:
+                *params = 32;
+                break;
+            case GR_GL_MAX_VERTEX_ATTRIBS:
+                *params = kDefaultMaxVertexAttribs;
+                break;
+            case GR_GL_MAX_VARYING_VECTORS:
+                *params = kDefaultMaxVaryingVectors;
+                break;
+            case GR_GL_NUM_EXTENSIONS: {
+                GrGLint i = 0;
+                while (kExtensions[i++]);
+                *params = i;
+                break;
+            }
+            default:
+                SkFAIL("Unexpected pname to GetIntegerv");
+        }
+    }
+
+    GrGLvoid getProgramiv(GrGLuint program, GrGLenum pname, GrGLint* params) override {
+        this->getShaderOrProgramiv(program, pname, params);
+    }
+
+    GrGLvoid getProgramInfoLog(GrGLuint program, GrGLsizei bufsize, GrGLsizei* length,
+                               char* infolog) override {
+        this->getInfoLog(program, bufsize, length, infolog);
+    }
+
+    GrGLvoid getMultisamplefv(GrGLenum pname, GrGLuint index, GrGLfloat* val) override {
+        val[0] = val[1] = 0.5f;
+    }
+
+    GrGLvoid getQueryiv(GrGLenum GLtarget, GrGLenum pname, GrGLint *params) override {
+        switch (pname) {
+            case GR_GL_CURRENT_QUERY:
+                *params = 0;
+                break;
+            case GR_GL_QUERY_COUNTER_BITS:
+                *params = 32;
+                break;
+            default:
+                SkFAIL("Unexpected pname passed GetQueryiv.");
+        }
+    }
+
+    GrGLvoid getQueryObjecti64v(GrGLuint id, GrGLenum pname, GrGLint64 *params) override {
+        queryResult(id, pname, params);
+    }
+
+    GrGLvoid getQueryObjectiv(GrGLuint id, GrGLenum pname, GrGLint *params) override {
+        queryResult(id, pname, params);
+    }
+
+    GrGLvoid getQueryObjectui64v(GrGLuint id, GrGLenum pname, GrGLuint64 *params) override {
+        queryResult(id, pname, params);
+    }
+
+    GrGLvoid getQueryObjectuiv(GrGLuint id, GrGLenum pname, GrGLuint *params) override {
+        queryResult(id, pname, params);
+    }
 
+    GrGLvoid getShaderiv(GrGLuint shader, GrGLenum pname, GrGLint* params) override {
+        this->getShaderOrProgramiv(shader, pname, params);
+    }
+
+    GrGLvoid getShaderInfoLog(GrGLuint shader, GrGLsizei bufsize, GrGLsizei* length,
+                              char* infolog) override {
+        this->getInfoLog(shader, bufsize, length, infolog);
+    }
+
+    const GrGLubyte* getString(GrGLenum name) override {
+        switch (name) {
+            case GR_GL_EXTENSIONS:
+                return CombinedExtensionString();
+            case GR_GL_VERSION:
+                return (const GrGLubyte*)"4.0 Debug GL";
+            case GR_GL_SHADING_LANGUAGE_VERSION:
+                return (const GrGLubyte*)"4.20.8 Debug GLSL";
+            case GR_GL_VENDOR:
+                return (const GrGLubyte*)"Debug Vendor";
+            case GR_GL_RENDERER:
+                return (const GrGLubyte*)"The Debug (Non-)Renderer";
+            default:
+                SkFAIL("Unexpected name passed to GetString");
+                return nullptr;
+        }
+    }
+
+    const GrGLubyte* getStringi(GrGLenum name, GrGLuint i) override {
+        switch (name) {
+            case GR_GL_EXTENSIONS: {
+                GrGLint count;
+                this->getIntegerv(GR_GL_NUM_EXTENSIONS, &count);
+                if ((GrGLint)i <= count) {
+                    return (const GrGLubyte*) kExtensions[i];
+                } else {
+                    return nullptr;
+                }
+            }
+            default:
+                SkFAIL("Unexpected name passed to GetStringi");
+                return nullptr;
+        }
+    }
+
+    GrGLvoid getTexLevelParameteriv(GrGLenum target, GrGLint level, GrGLenum pname,
+                                    GrGLint* params) override {
+        // we used to use this to query stuff about externally created textures,
+        // now we just require clients to tell us everything about the texture.
+        SkFAIL("Should never query texture parameters.");
+    }
+
+    GrGLint getUniformLocation(GrGLuint program, const char* name) override {
+        return ++fCurrUniformLocation;
+    }
+
+    GrGLvoid* mapBufferRange(GrGLenum target, GrGLintptr offset, GrGLsizeiptr length,
+                             GrGLbitfield access) override {
+        GrGLuint id = 0;
+        switch (target) {
+            case GR_GL_ARRAY_BUFFER:
+                id = fCurrArrayBuffer;
+                break;
+            case GR_GL_ELEMENT_ARRAY_BUFFER:
+                id = fCurrElementArrayBuffer;
+                break;
+            case GR_GL_PIXEL_PACK_BUFFER:
+                id = fCurrPixelPackBuffer;
+                break;
+            case GR_GL_PIXEL_UNPACK_BUFFER:
+                id = fCurrPixelUnpackBuffer;
+                break;
+        }
+
+        if (id > 0) {
+            // We just ignore the offset and length here.
+            BufferObj* buffer = fBufferManager.lookUp(id);
+            SkASSERT(!buffer->mapped());
+            buffer->setMapped(true);
+            return buffer->dataPtr();
+        }
+        return nullptr;
+    }
+
+    GrGLvoid* mapBuffer(GrGLenum target, GrGLenum access) override {
+        GrGLuint id = 0;
+        switch (target) {
+            case GR_GL_ARRAY_BUFFER:
+                id = fCurrArrayBuffer;
+                break;
+            case GR_GL_ELEMENT_ARRAY_BUFFER:
+                id = fCurrElementArrayBuffer;
+                break;
+            case GR_GL_PIXEL_PACK_BUFFER:
+                id = fCurrPixelPackBuffer;
+                break;
+            case GR_GL_PIXEL_UNPACK_BUFFER:
+                id = fCurrPixelUnpackBuffer;
+                break;
+        }
+
+        if (id > 0) {
+            BufferObj* buffer = fBufferManager.lookUp(id);
+            SkASSERT(!buffer->mapped());
+            buffer->setMapped(true);
+            return buffer->dataPtr();
+        }
+
+        SkASSERT(false);
+        return nullptr;            // no buffer bound to target
+    }
+
+    GrGLboolean unmapBuffer(GrGLenum target) override {
+        GrGLuint id = 0;
+        switch (target) {
+            case GR_GL_ARRAY_BUFFER:
+                id = fCurrArrayBuffer;
+                break;
+            case GR_GL_ELEMENT_ARRAY_BUFFER:
+                id = fCurrElementArrayBuffer;
+                break;
+            case GR_GL_PIXEL_PACK_BUFFER:
+                id = fCurrPixelPackBuffer;
+                break;
+            case GR_GL_PIXEL_UNPACK_BUFFER:
+                id = fCurrPixelUnpackBuffer;
+                break;
+        }
+        if (id > 0) {
+            BufferObj* buffer = fBufferManager.lookUp(id);
+            SkASSERT(buffer->mapped());
+            buffer->setMapped(false);
+            return GR_GL_TRUE;
+        }
+
+        GrAlwaysAssert(false);
+        return GR_GL_FALSE; // GR_GL_INVALID_OPERATION;
+    }
+
+    GrGLvoid getBufferParameteriv(GrGLenum target, GrGLenum pname, GrGLint* params) override {
+        switch (pname) {
+            case GR_GL_BUFFER_MAPPED: {
+                *params = GR_GL_FALSE;
+                GrGLuint id = 0;
+                switch (target) {
+                    case GR_GL_ARRAY_BUFFER:
+                        id = fCurrArrayBuffer;
+                        break;
+                    case GR_GL_ELEMENT_ARRAY_BUFFER:
+                        id = fCurrElementArrayBuffer;
+                        break;
+                    case GR_GL_PIXEL_PACK_BUFFER:
+                        id = fCurrPixelPackBuffer;
+                        break;
+                    case GR_GL_PIXEL_UNPACK_BUFFER:
+                        id = fCurrPixelUnpackBuffer;
+                        break;
+                }
+                if (id > 0) {
+                    BufferObj* buffer = fBufferManager.lookUp(id);
+                    if (buffer->mapped()) {
+                        *params = GR_GL_TRUE;
+                    }
+                }
+                break; }
+            default:
+                SkFAIL("Unexpected pname to GetBufferParamateriv");
+                break;
+        }
+    };
+
+private:
     BufferManager   fBufferManager;
     GrGLuint        fCurrArrayBuffer;
     GrGLuint        fCurrElementArrayBuffer;
+    GrGLuint        fCurrPixelPackBuffer;
+    GrGLuint        fCurrPixelUnpackBuffer;
     GrGLuint        fCurrProgramID;
     GrGLuint        fCurrShaderID;
+    GrGLuint        fCurrGenericID;
+    GrGLuint        fCurrUniformLocation;
 
-    static ThreadContext* Get() {
-        return reinterpret_cast<ThreadContext*>(SkTLS::Get(Create, Delete));
-    }
+    // the OpenGLES 2.0 spec says this must be >= 128
+    static const GrGLint kDefaultMaxVertexUniformVectors = 128;
 
-    ThreadContext()
-        : fCurrArrayBuffer(0)
-        , fCurrElementArrayBuffer(0)
-        , fCurrProgramID(0)
-        , fCurrShaderID(0) {}
+    // the OpenGLES 2.0 spec says this must be >=16
+    static const GrGLint kDefaultMaxFragmentUniformVectors = 16;
 
-private:
-    static void* Create() { return new ThreadContext; }
-    static void Delete(void* context) { delete reinterpret_cast<ThreadContext*>(context); }
-};
+    // the OpenGLES 2.0 spec says this must be >= 8
+    static const GrGLint kDefaultMaxVertexAttribs = 8;
 
-// Functions not declared in GrGLBogusInterface.h (not common with the Debug GL interface).
-
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLActiveTexture(GrGLenum texture) {}
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLAttachShader(GrGLuint program, GrGLuint shader) {}
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLBeginQuery(GrGLenum target, GrGLuint id) {}
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLBindAttribLocation(GrGLuint program, GrGLuint index, const char* name) {}
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLBindTexture(GrGLenum target, GrGLuint texture) {}
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLBindVertexArray(GrGLuint id) {}
-
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLGenBuffers(GrGLsizei n, GrGLuint* ids) {
-    ThreadContext* ctx = ThreadContext::Get();
-    for (int i = 0; i < n; ++i) {
-        BufferObj* buffer = ctx->fBufferManager.create();
-        ids[i] = buffer->id();
-    }
-}
-
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLGenerateMipmap(GrGLenum target) {}
-
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLBufferData(GrGLenum target,
-                                              GrGLsizeiptr size,
-                                              const GrGLvoid* data,
-                                              GrGLenum usage) {
-    ThreadContext* ctx = ThreadContext::Get();
-    GrGLuint id = 0;
-
-    switch (target) {
-    case GR_GL_ARRAY_BUFFER:
-        id = ctx->fCurrArrayBuffer;
-        break;
-    case GR_GL_ELEMENT_ARRAY_BUFFER:
-        id = ctx->fCurrElementArrayBuffer;
-        break;
-    default:
-        SkFAIL("Unexpected target to nullGLBufferData");
-        break;
-    }
-
-    if (id > 0) {
-        BufferObj* buffer = ctx->fBufferManager.lookUp(id);
-        buffer->allocate(size, (const GrGLchar*) data);
-    }
-}
-
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLPixelStorei(GrGLenum pname, GrGLint param) {}
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLReadPixels(GrGLint x, GrGLint y, GrGLsizei width, GrGLsizei height, GrGLenum format, GrGLenum type, GrGLvoid* pixels) {}
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLUseProgram(GrGLuint program) {}
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLViewport(GrGLint x, GrGLint y, GrGLsizei width, GrGLsizei height) {}
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLBindFramebuffer(GrGLenum target, GrGLuint framebuffer) {}
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLBindRenderbuffer(GrGLenum target, GrGLuint renderbuffer) {}
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLDeleteFramebuffers(GrGLsizei n, const GrGLuint *framebuffers) {}
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLDeleteRenderbuffers(GrGLsizei n, const GrGLuint *renderbuffers) {}
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLFramebufferRenderbuffer(GrGLenum target, GrGLenum attachment, GrGLenum renderbuffertarget, GrGLuint renderbuffer) {}
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLFramebufferTexture2D(GrGLenum target, GrGLenum attachment, GrGLenum textarget, GrGLuint texture, GrGLint level) {}
-
-GrGLuint GR_GL_FUNCTION_TYPE nullGLCreateProgram() {
-    return ++ThreadContext::Get()->fCurrProgramID;
-}
-
-GrGLuint GR_GL_FUNCTION_TYPE nullGLCreateShader(GrGLenum type) {
-    return ++ThreadContext::Get()->fCurrShaderID;
-}
-
-// same delete used for shaders and programs
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLDelete(GrGLuint program) {
-}
-
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLBindBuffer(GrGLenum target, GrGLuint buffer) {
-    ThreadContext* ctx = ThreadContext::Get();
-    switch (target) {
-    case GR_GL_ARRAY_BUFFER:
-        ctx->fCurrArrayBuffer = buffer;
-        break;
-    case GR_GL_ELEMENT_ARRAY_BUFFER:
-        ctx->fCurrElementArrayBuffer = buffer;
-        break;
-    }
-}
-
-// deleting a bound buffer has the side effect of binding 0
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLDeleteBuffers(GrGLsizei n, const GrGLuint* ids) {
-    ThreadContext* ctx = ThreadContext::Get();
-    for (int i = 0; i < n; ++i) {
-        if (ids[i] == ctx->fCurrArrayBuffer) {
-            ctx->fCurrArrayBuffer = 0;
-        }
-        if (ids[i] == ctx->fCurrElementArrayBuffer) {
-            ctx->fCurrElementArrayBuffer = 0;
-        }
+    // the OpenGLES 2.0 spec says this must be >= 8
+    static const GrGLint kDefaultMaxVaryingVectors = 8;
 
-        BufferObj* buffer = ctx->fBufferManager.lookUp(ids[i]);
-        ctx->fBufferManager.free(buffer);
-    }
-}
-
-GrGLvoid* GR_GL_FUNCTION_TYPE nullGLMapBufferRange(GrGLenum target, GrGLintptr offset,
-                                                   GrGLsizeiptr length, GrGLbitfield access) {
-    ThreadContext* ctx = ThreadContext::Get();
-    GrGLuint id = 0;
-    switch (target) {
-        case GR_GL_ARRAY_BUFFER:
-            id = ctx->fCurrArrayBuffer;
-            break;
-        case GR_GL_ELEMENT_ARRAY_BUFFER:
-            id = ctx->fCurrElementArrayBuffer;
-            break;
-    }
-
-    if (id > 0) {
-        // We just ignore the offset and length here.
-        BufferObj* buffer = ctx->fBufferManager.lookUp(id);
-        SkASSERT(!buffer->mapped());
-        buffer->setMapped(true);
-        return buffer->dataPtr();
-    }
-    return nullptr;
-}
-
-GrGLvoid* GR_GL_FUNCTION_TYPE nullGLMapBuffer(GrGLenum target, GrGLenum access) {
-    ThreadContext* ctx = ThreadContext::Get();
-    GrGLuint id = 0;
-    switch (target) {
-        case GR_GL_ARRAY_BUFFER:
-            id = ctx->fCurrArrayBuffer;
-            break;
-        case GR_GL_ELEMENT_ARRAY_BUFFER:
-            id = ctx->fCurrElementArrayBuffer;
-            break;
-    }
-
-    if (id > 0) {
-        BufferObj* buffer = ctx->fBufferManager.lookUp(id);
-        SkASSERT(!buffer->mapped());
-        buffer->setMapped(true);
-        return buffer->dataPtr();
-    }
-
-    SkASSERT(false);
-    return nullptr;            // no buffer bound to target
-}
-
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLFlushMappedBufferRange(GrGLenum target,
-                                                          GrGLintptr offset,
-                                                          GrGLsizeiptr length) {}
-
-
-GrGLboolean GR_GL_FUNCTION_TYPE nullGLUnmapBuffer(GrGLenum target) {
-    ThreadContext* ctx = ThreadContext::Get();
-    GrGLuint id = 0;
-    switch (target) {
-    case GR_GL_ARRAY_BUFFER:
-        id = ctx->fCurrArrayBuffer;
-        break;
-    case GR_GL_ELEMENT_ARRAY_BUFFER:
-        id = ctx->fCurrElementArrayBuffer;
-        break;
-    }
-    if (id > 0) {
-        BufferObj* buffer = ctx->fBufferManager.lookUp(id);
-        SkASSERT(buffer->mapped());
-        buffer->setMapped(false);
-        return GR_GL_TRUE;
-    }
-
-    GrAlwaysAssert(false);
-    return GR_GL_FALSE; // GR_GL_INVALID_OPERATION;
-}
-
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLGetBufferParameteriv(GrGLenum target, GrGLenum pname, GrGLint* params) {
-    ThreadContext* ctx = ThreadContext::Get();
-    switch (pname) {
-        case GR_GL_BUFFER_MAPPED: {
-            *params = GR_GL_FALSE;
-            GrGLuint id = 0;
-            switch (target) {
-                case GR_GL_ARRAY_BUFFER:
-                    id = ctx->fCurrArrayBuffer;
-                    break;
-                case GR_GL_ELEMENT_ARRAY_BUFFER:
-                    id = ctx->fCurrElementArrayBuffer;
-                    break;
-            }
-            if (id > 0) {
-                BufferObj* buffer = ctx->fBufferManager.lookUp(id);
-                if (buffer->mapped()) {
-                    *params = GR_GL_TRUE;
+    static const char* kExtensions[];
+
+    static const GrGLubyte* CombinedExtensionString() {
+        static SkString gExtString;
+        static SkMutex gMutex;
+        gMutex.acquire();
+        if (0 == gExtString.size()) {
+            int i = 0;
+            while (kExtensions[i]) {
+                if (i > 0) {
+                    gExtString.append(" ");
                 }
+                gExtString.append(kExtensions[i]);
+                ++i;
             }
-            break; }
-        default:
-            SkFAIL("Unexpected pname to GetBufferParamateriv");
-            break;
+        }
+        gMutex.release();
+        return (const GrGLubyte*) gExtString.c_str();
+    }
+
+    GrGLvoid genGenericIds(GrGLsizei n, GrGLuint* ids) {
+        for (int i = 0; i < n; ++i) {
+            ids[i] = ++fCurrGenericID;
+        }
+    }
+
+    GrGLvoid getInfoLog(GrGLuint object, GrGLsizei bufsize, GrGLsizei* length,
+                        char* infolog) {
+        if (length) {
+            *length = 0;
+        }
+        if (bufsize > 0) {
+            *infolog = 0;
+        }
+    }
+
+    GrGLvoid getShaderOrProgramiv(GrGLuint object,  GrGLenum pname, GrGLint* params) {
+        switch (pname) {
+            case GR_GL_LINK_STATUS:  // fallthru
+            case GR_GL_COMPILE_STATUS:
+                *params = GR_GL_TRUE;
+                break;
+            case GR_GL_INFO_LOG_LENGTH:
+                *params = 0;
+                break;
+                // we don't expect any other pnames
+            default:
+                SkFAIL("Unexpected pname to GetProgramiv");
+                break;
+        }
+    }
+
+    template <typename T>
+    void queryResult(GrGLenum GLtarget, GrGLenum pname, T *params) {
+        switch (pname) {
+            case GR_GL_QUERY_RESULT_AVAILABLE:
+                *params = GR_GL_TRUE;
+                break;
+            case GR_GL_QUERY_RESULT:
+                *params = 0;
+                break;
+            default:
+                SkFAIL("Unexpected pname passed to GetQueryObject.");
+                break;
+        }
     }
 };
 
-} // end anonymous namespace
-
-const GrGLInterface* GrGLCreateNullInterface() {
-    GrGLInterface* interface = new GrGLInterface;
-
-    interface->fStandard = kGL_GrGLStandard;
-
-    GrGLInterface::Functions* functions = &interface->fFunctions;
-    functions->fActiveTexture = nullGLActiveTexture;
-    functions->fAttachShader = nullGLAttachShader;
-    functions->fBeginQuery = nullGLBeginQuery;
-    functions->fBindAttribLocation = nullGLBindAttribLocation;
-    functions->fBindBuffer = nullGLBindBuffer;
-    functions->fBindFragDataLocation = noOpGLBindFragDataLocation;
-    functions->fBindTexture = nullGLBindTexture;
-    functions->fBindVertexArray = nullGLBindVertexArray;
-    functions->fBlendColor = noOpGLBlendColor;
-    functions->fBlendEquation = noOpGLBlendEquation;
-    functions->fBlendFunc = noOpGLBlendFunc;
-    functions->fBufferData = nullGLBufferData;
-    functions->fBufferSubData = noOpGLBufferSubData;
-    functions->fClear = noOpGLClear;
-    functions->fClearColor = noOpGLClearColor;
-    functions->fClearStencil = noOpGLClearStencil;
-    functions->fColorMask = noOpGLColorMask;
-    functions->fCompileShader = noOpGLCompileShader;
-    functions->fCompressedTexImage2D = noOpGLCompressedTexImage2D;
-    functions->fCompressedTexSubImage2D = noOpGLCompressedTexSubImage2D;
-    functions->fCopyTexSubImage2D = noOpGLCopyTexSubImage2D;
-    functions->fCreateProgram = nullGLCreateProgram;
-    functions->fCreateShader = nullGLCreateShader;
-    functions->fCullFace = noOpGLCullFace;
-    functions->fDeleteBuffers = nullGLDeleteBuffers;
-    functions->fDeleteProgram = nullGLDelete;
-    functions->fDeleteQueries = noOpGLDeleteIds;
-    functions->fDeleteShader = nullGLDelete;
-    functions->fDeleteTextures = noOpGLDeleteIds;
-    functions->fDeleteVertexArrays = noOpGLDeleteIds;
-    functions->fDepthMask = noOpGLDepthMask;
-    functions->fDisable = noOpGLDisable;
-    functions->fDisableVertexAttribArray = noOpGLDisableVertexAttribArray;
-    functions->fDrawArrays = noOpGLDrawArrays;
-    functions->fDrawArraysInstanced = noOpGLDrawArraysInstanced;
-    functions->fDrawBuffer = noOpGLDrawBuffer;
-    functions->fDrawBuffers = noOpGLDrawBuffers;
-    functions->fDrawElements = noOpGLDrawElements;
-    functions->fDrawElementsInstanced = noOpGLDrawElementsInstanced;
-    functions->fEnable = noOpGLEnable;
-    functions->fEnableVertexAttribArray = noOpGLEnableVertexAttribArray;
-    functions->fEndQuery = noOpGLEndQuery;
-    functions->fFinish = noOpGLFinish;
-    functions->fFlush = noOpGLFlush;
-    functions->fFlushMappedBufferRange = nullGLFlushMappedBufferRange;
-    functions->fFrontFace = noOpGLFrontFace;
-    functions->fGenBuffers = nullGLGenBuffers;
-    functions->fGenerateMipmap = nullGLGenerateMipmap;
-    functions->fGenQueries = noOpGLGenIds;
-    functions->fGenTextures = noOpGLGenIds;
-    functions->fGenVertexArrays = noOpGLGenIds;
-    functions->fGetBufferParameteriv = nullGLGetBufferParameteriv;
-    functions->fGetError = noOpGLGetError;
-    functions->fGetIntegerv = noOpGLGetIntegerv;
-    functions->fGetMultisamplefv = noOpGLGetMultisamplefv;
-    functions->fGetQueryObjecti64v = noOpGLGetQueryObjecti64v;
-    functions->fGetQueryObjectiv = noOpGLGetQueryObjectiv;
-    functions->fGetQueryObjectui64v = noOpGLGetQueryObjectui64v;
-    functions->fGetQueryObjectuiv = noOpGLGetQueryObjectuiv;
-    functions->fGetQueryiv = noOpGLGetQueryiv;
-    functions->fGetProgramInfoLog = noOpGLGetInfoLog;
-    functions->fGetProgramiv = noOpGLGetShaderOrProgramiv;
-    functions->fGetShaderInfoLog = noOpGLGetInfoLog;
-    functions->fGetShaderiv = noOpGLGetShaderOrProgramiv;
-    functions->fGetString = noOpGLGetString;
-    functions->fGetStringi = noOpGLGetStringi;
-    functions->fGetTexLevelParameteriv = noOpGLGetTexLevelParameteriv;
-    functions->fGetUniformLocation = noOpGLGetUniformLocation;
-    functions->fInsertEventMarker = noOpGLInsertEventMarker;
-    functions->fLineWidth = noOpGLLineWidth;
-    functions->fLinkProgram = noOpGLLinkProgram;
-    functions->fMapBuffer = nullGLMapBuffer;
-    functions->fMapBufferRange = nullGLMapBufferRange;
-    functions->fPixelStorei = nullGLPixelStorei;
-    functions->fPopGroupMarker = noOpGLPopGroupMarker;
-    functions->fPushGroupMarker = noOpGLPushGroupMarker;
-    functions->fQueryCounter = noOpGLQueryCounter;
-    functions->fReadBuffer = noOpGLReadBuffer;
-    functions->fReadPixels = nullGLReadPixels;
-    functions->fScissor = noOpGLScissor;
-    functions->fShaderSource = noOpGLShaderSource;
-    functions->fStencilFunc = noOpGLStencilFunc;
-    functions->fStencilFuncSeparate = noOpGLStencilFuncSeparate;
-    functions->fStencilMask = noOpGLStencilMask;
-    functions->fStencilMaskSeparate = noOpGLStencilMaskSeparate;
-    functions->fStencilOp = noOpGLStencilOp;
-    functions->fStencilOpSeparate = noOpGLStencilOpSeparate;
-    functions->fTexBuffer = noOpGLTexBuffer;
-    functions->fTexImage2D = noOpGLTexImage2D;
-    functions->fTexParameteri = noOpGLTexParameteri;
-    functions->fTexParameteriv = noOpGLTexParameteriv;
-    functions->fTexSubImage2D = noOpGLTexSubImage2D;
-    functions->fTexStorage2D = noOpGLTexStorage2D;
-    functions->fDiscardFramebuffer = noOpGLDiscardFramebuffer;
-    functions->fUniform1f = noOpGLUniform1f;
-    functions->fUniform1i = noOpGLUniform1i;
-    functions->fUniform1fv = noOpGLUniform1fv;
-    functions->fUniform1iv = noOpGLUniform1iv;
-    functions->fUniform2f = noOpGLUniform2f;
-    functions->fUniform2i = noOpGLUniform2i;
-    functions->fUniform2fv = noOpGLUniform2fv;
-    functions->fUniform2iv = noOpGLUniform2iv;
-    functions->fUniform3f = noOpGLUniform3f;
-    functions->fUniform3i = noOpGLUniform3i;
-    functions->fUniform3fv = noOpGLUniform3fv;
-    functions->fUniform3iv = noOpGLUniform3iv;
-    functions->fUniform4f = noOpGLUniform4f;
-    functions->fUniform4i = noOpGLUniform4i;
-    functions->fUniform4fv = noOpGLUniform4fv;
-    functions->fUniform4iv = noOpGLUniform4iv;
-    functions->fUniformMatrix2fv = noOpGLUniformMatrix2fv;
-    functions->fUniformMatrix3fv = noOpGLUniformMatrix3fv;
-    functions->fUniformMatrix4fv = noOpGLUniformMatrix4fv;
-    functions->fUnmapBuffer = nullGLUnmapBuffer;
-    functions->fUseProgram = nullGLUseProgram;
-    functions->fVertexAttrib1f = noOpGLVertexAttrib1f;
-    functions->fVertexAttrib2fv = noOpGLVertexAttrib2fv;
-    functions->fVertexAttrib3fv = noOpGLVertexAttrib3fv;
-    functions->fVertexAttrib4fv = noOpGLVertexAttrib4fv;
-    functions->fVertexAttribDivisor = noOpGLVertexAttribDivisor;
-    functions->fVertexAttribIPointer = noOpGLVertexAttribIPointer;
-    functions->fVertexAttribPointer = noOpGLVertexAttribPointer;
-    functions->fViewport = nullGLViewport;
-    functions->fBindFramebuffer = nullGLBindFramebuffer;
-    functions->fBindRenderbuffer = nullGLBindRenderbuffer;
-    functions->fCheckFramebufferStatus = noOpGLCheckFramebufferStatus;
-    functions->fDeleteFramebuffers = nullGLDeleteFramebuffers;
-    functions->fDeleteRenderbuffers = nullGLDeleteRenderbuffers;
-    functions->fFramebufferRenderbuffer = nullGLFramebufferRenderbuffer;
-    functions->fFramebufferTexture2D = nullGLFramebufferTexture2D;
-    functions->fGenFramebuffers = noOpGLGenIds;
-    functions->fGenRenderbuffers = noOpGLGenIds;
-    functions->fGetFramebufferAttachmentParameteriv = noOpGLGetFramebufferAttachmentParameteriv;
-    functions->fGetRenderbufferParameteriv = noOpGLGetRenderbufferParameteriv;
-    functions->fRenderbufferStorage = noOpGLRenderbufferStorage;
-    functions->fRenderbufferStorageMultisample = noOpGLRenderbufferStorageMultisample;
-    functions->fBlitFramebuffer = noOpGLBlitFramebuffer;
-    functions->fResolveMultisampleFramebuffer = noOpGLResolveMultisampleFramebuffer;
-    functions->fMatrixLoadf = noOpGLMatrixLoadf;
-    functions->fMatrixLoadIdentity = noOpGLMatrixLoadIdentity;
-    functions->fBindFragDataLocationIndexed = noOpGLBindFragDataLocationIndexed;
-
-    interface->fExtensions.init(kGL_GrGLStandard, functions->fGetString, functions->fGetStringi,
-                                functions->fGetIntegerv, nullptr, GR_EGL_NO_DISPLAY);
-    return interface;
-}
+const char* NullInterface::kExtensions[] = {
+    "GL_ARB_framebuffer_object",
+    "GL_ARB_blend_func_extended",
+    "GL_ARB_timer_query",
+    "GL_ARB_draw_buffers",
+    "GL_ARB_occlusion_query",
+    "GL_EXT_stencil_wrap",
+    nullptr, // signifies the end of the array.
+};
+
+}  // anonymous namespace
+
+const GrGLInterface* GrGLCreateNullInterface() { return new NullInterface; }
diff --git a/src/gpu/gl/GrGLTestInterface.cpp b/src/gpu/gl/GrGLTestInterface.cpp
new file mode 100644
index 0000000000..7200981356
--- /dev/null
+++ b/src/gpu/gl/GrGLTestInterface.cpp
@@ -0,0 +1,320 @@
+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#include <functional>
+#include "GrGLTestInterface.h"
+
+namespace {
+template<typename R, typename... A>
+std::function<R(A...)> bind_to_member(GrGLTestInterface* interface, R (GrGLTestInterface::*member)(A...)) {
+    return [interface, member] (A... a) -> R { return (interface->*member)(a...); };
+}
+}  // anonymous namespace
+
+GrGLTestInterface::GrGLTestInterface() {
+    fFunctions.fActiveTexture = bind_to_member(this, &GrGLTestInterface::activeTexture);
+    fFunctions.fAttachShader = bind_to_member(this, &GrGLTestInterface::attachShader);
+    fFunctions.fBeginQuery = bind_to_member(this, &GrGLTestInterface::beginQuery);
+    fFunctions.fBindAttribLocation = bind_to_member(this, &GrGLTestInterface::bindAttribLocation);
+    fFunctions.fBindBuffer = bind_to_member(this, &GrGLTestInterface::bindBuffer);
+    fFunctions.fBindFramebuffer = bind_to_member(this, &GrGLTestInterface::bindFramebuffer);
+    fFunctions.fBindRenderbuffer = bind_to_member(this, &GrGLTestInterface::bindRenderbuffer);
+    fFunctions.fBindTexture = bind_to_member(this, &GrGLTestInterface::bindTexture);
+    fFunctions.fBindFragDataLocation = bind_to_member(this, &GrGLTestInterface::bindFragDataLocation);
+    fFunctions.fBindFragDataLocationIndexed = bind_to_member(this, &GrGLTestInterface::bindFragDataLocationIndexed);
+    fFunctions.fBindVertexArray = bind_to_member(this, &GrGLTestInterface::bindVertexArray);
+    fFunctions.fBlendBarrier = bind_to_member(this, &GrGLTestInterface::blendBarrier);
+    fFunctions.fBlendColor = bind_to_member(this, &GrGLTestInterface::blendColor);
+    fFunctions.fBlendEquation = bind_to_member(this, &GrGLTestInterface::blendEquation);
+    fFunctions.fBlendFunc = bind_to_member(this, &GrGLTestInterface::blendFunc);
+    fFunctions.fBlitFramebuffer = bind_to_member(this, &GrGLTestInterface::blitFramebuffer);
+    fFunctions.fBufferData = bind_to_member(this, &GrGLTestInterface::bufferData);
+    fFunctions.fBufferSubData = bind_to_member(this, &GrGLTestInterface::bufferSubData);
+    fFunctions.fCheckFramebufferStatus = bind_to_member(this, &GrGLTestInterface::checkFramebufferStatus);
+    fFunctions.fClear = bind_to_member(this, &GrGLTestInterface::clear);
+    fFunctions.fClearColor = bind_to_member(this, &GrGLTestInterface::clearColor);
+    fFunctions.fClearStencil = bind_to_member(this, &GrGLTestInterface::clearStencil);
+    fFunctions.fColorMask = bind_to_member(this, &GrGLTestInterface::colorMask);
+    fFunctions.fCompileShader = bind_to_member(this, &GrGLTestInterface::compileShader);
+    fFunctions.fCompressedTexImage2D = bind_to_member(this, &GrGLTestInterface::compressedTexImage2D);
+    fFunctions.fCompressedTexSubImage2D = bind_to_member(this, &GrGLTestInterface::compressedTexSubImage2D);
+    fFunctions.fCopyTexSubImage2D = bind_to_member(this, &GrGLTestInterface::copyTexSubImage2D);
+    fFunctions.fCreateProgram = bind_to_member(this, &GrGLTestInterface::createProgram);
+    fFunctions.fCreateShader = bind_to_member(this, &GrGLTestInterface::createShader);
+    fFunctions.fCullFace = bind_to_member(this, &GrGLTestInterface::cullFace);
+    fFunctions.fDeleteBuffers = bind_to_member(this, &GrGLTestInterface::deleteBuffers);
+    fFunctions.fDeleteFramebuffers = bind_to_member(this, &GrGLTestInterface::deleteFramebuffers);
+    fFunctions.fDeleteProgram = bind_to_member(this, &GrGLTestInterface::deleteProgram);
+    fFunctions.fDeleteQueries = bind_to_member(this, &GrGLTestInterface::deleteQueries);
+    fFunctions.fDeleteRenderbuffers = bind_to_member(this, &GrGLTestInterface::deleteRenderbuffers);
+    fFunctions.fDeleteShader = bind_to_member(this, &GrGLTestInterface::deleteShader);
+    fFunctions.fDeleteTextures = bind_to_member(this, &GrGLTestInterface::deleteTextures);
+    fFunctions.fDeleteVertexArrays = bind_to_member(this, &GrGLTestInterface::deleteVertexArrays);
+    fFunctions.fDepthMask = bind_to_member(this, &GrGLTestInterface::depthMask);
+    fFunctions.fDisable = bind_to_member(this, &GrGLTestInterface::disable);
+    fFunctions.fDisableVertexAttribArray = bind_to_member(this, &GrGLTestInterface::disableVertexAttribArray);
+    fFunctions.fDrawArrays = bind_to_member(this, &GrGLTestInterface::drawArrays);
+    fFunctions.fDrawArraysInstanced = bind_to_member(this, &GrGLTestInterface::drawArraysInstanced);
+    fFunctions.fDrawArraysIndirect = bind_to_member(this, &GrGLTestInterface::drawArraysIndirect);
+    fFunctions.fDrawBuffer = bind_to_member(this, &GrGLTestInterface::drawBuffer);
+    fFunctions.fDrawBuffers = bind_to_member(this, &GrGLTestInterface::drawBuffers);
+    fFunctions.fDrawElements = bind_to_member(this, &GrGLTestInterface::drawElements);
+    fFunctions.fDrawElementsInstanced = bind_to_member(this, &GrGLTestInterface::drawElementsInstanced);
+    fFunctions.fDrawElementsIndirect = bind_to_member(this, &GrGLTestInterface::drawElementsIndirect);
+    fFunctions.fEnable = bind_to_member(this, &GrGLTestInterface::enable);
+    fFunctions.fEnableVertexAttribArray = bind_to_member(this, &GrGLTestInterface::enableVertexAttribArray);
+    fFunctions.fEndQuery = bind_to_member(this, &GrGLTestInterface::endQuery);
+    fFunctions.fFinish = bind_to_member(this, &GrGLTestInterface::finish);
+    fFunctions.fFlush = bind_to_member(this, &GrGLTestInterface::flush);
+    fFunctions.fFlushMappedBufferRange = bind_to_member(this, &GrGLTestInterface::flushMappedBufferRange);
+    fFunctions.fFramebufferRenderbuffer = bind_to_member(this, &GrGLTestInterface::framebufferRenderbuffer);
+    fFunctions.fFramebufferTexture2D = bind_to_member(this, &GrGLTestInterface::framebufferTexture2D);
+    fFunctions.fFramebufferTexture2DMultisample = bind_to_member(this, &GrGLTestInterface::framebufferTexture2DMultisample);
+    fFunctions.fFrontFace = bind_to_member(this, &GrGLTestInterface::frontFace);
+    fFunctions.fGenBuffers = bind_to_member(this, &GrGLTestInterface::genBuffers);
+    fFunctions.fGenFramebuffers = bind_to_member(this, &GrGLTestInterface::genFramebuffers);
+    fFunctions.fGenerateMipmap = bind_to_member(this, &GrGLTestInterface::generateMipmap);
+    fFunctions.fGenQueries = bind_to_member(this, &GrGLTestInterface::genQueries);
+    fFunctions.fGenRenderbuffers = bind_to_member(this, &GrGLTestInterface::genRenderbuffers);
+    fFunctions.fGenTextures = bind_to_member(this, &GrGLTestInterface::genTextures);
+    fFunctions.fGenVertexArrays = bind_to_member(this, &GrGLTestInterface::genVertexArrays);
+    fFunctions.fGetBufferParameteriv = bind_to_member(this, &GrGLTestInterface::getBufferParameteriv);
+    fFunctions.fGetError = bind_to_member(this, &GrGLTestInterface::getError);
+    fFunctions.fGetFramebufferAttachmentParameteriv = bind_to_member(this, &GrGLTestInterface::getFramebufferAttachmentParameteriv);
+    fFunctions.fGetIntegerv = bind_to_member(this, &GrGLTestInterface::getIntegerv);
+    fFunctions.fGetMultisamplefv = bind_to_member(this, &GrGLTestInterface::getMultisamplefv);
+    fFunctions.fGetProgramInfoLog = bind_to_member(this, &GrGLTestInterface::getProgramInfoLog);
+    fFunctions.fGetProgramiv = bind_to_member(this, &GrGLTestInterface::getProgramiv);
+    fFunctions.fGetQueryiv = bind_to_member(this, &GrGLTestInterface::getQueryiv);
+    fFunctions.fGetQueryObjecti64v = bind_to_member(this, &GrGLTestInterface::getQueryObjecti64v);
+    fFunctions.fGetQueryObjectiv = bind_to_member(this, &GrGLTestInterface::getQueryObjectiv);
+    fFunctions.fGetQueryObjectui64v = bind_to_member(this, &GrGLTestInterface::getQueryObjectui64v);
+    fFunctions.fGetQueryObjectuiv = bind_to_member(this, &GrGLTestInterface::getQueryObjectuiv);
+    fFunctions.fGetRenderbufferParameteriv = bind_to_member(this, &GrGLTestInterface::getRenderbufferParameteriv);
+    fFunctions.fGetShaderInfoLog = bind_to_member(this, &GrGLTestInterface::getShaderInfoLog);
+    fFunctions.fGetShaderiv = bind_to_member(this, &GrGLTestInterface::getShaderiv);
+    fFunctions.fGetShaderPrecisionFormat = bind_to_member(this, &GrGLTestInterface::getShaderPrecisionFormat);
+    fFunctions.fGetString = bind_to_member(this, &GrGLTestInterface::getString);
+    fFunctions.fGetStringi = bind_to_member(this, &GrGLTestInterface::getStringi);
+    fFunctions.fGetTexLevelParameteriv = bind_to_member(this, &GrGLTestInterface::getTexLevelParameteriv);
+    fFunctions.fGetUniformLocation = bind_to_member(this, &GrGLTestInterface::getUniformLocation);
+    fFunctions.fInsertEventMarker = bind_to_member(this, &GrGLTestInterface::insertEventMarker);
+    fFunctions.fInvalidateBufferData = bind_to_member(this, &GrGLTestInterface::invalidateBufferData);
+    fFunctions.fInvalidateBufferSubData = bind_to_member(this, &GrGLTestInterface::invalidateBufferSubData);
+    fFunctions.fInvalidateFramebuffer = bind_to_member(this, &GrGLTestInterface::invalidateFramebuffer);
+    fFunctions.fInvalidateSubFramebuffer = bind_to_member(this, &GrGLTestInterface::invalidateSubFramebuffer);
+    fFunctions.fInvalidateTexImage = bind_to_member(this, &GrGLTestInterface::invalidateTexImage);
+    fFunctions.fInvalidateTexSubImage = bind_to_member(this, &GrGLTestInterface::invalidateTexSubImage);
+    fFunctions.fIsTexture = bind_to_member(this, &GrGLTestInterface::isTexture);
+    fFunctions.fLineWidth = bind_to_member(this, &GrGLTestInterface::lineWidth);
+    fFunctions.fLinkProgram = bind_to_member(this, &GrGLTestInterface::linkProgram);
+    fFunctions.fMapBuffer = bind_to_member(this, &GrGLTestInterface::mapBuffer);
+    fFunctions.fMapBufferRange = bind_to_member(this, &GrGLTestInterface::mapBufferRange);
+    fFunctions.fMapBufferSubData = bind_to_member(this, &GrGLTestInterface::mapBufferSubData);
+    fFunctions.fMapTexSubImage2D = bind_to_member(this, &GrGLTestInterface::mapTexSubImage2D);
+    fFunctions.fPixelStorei = bind_to_member(this, &GrGLTestInterface::pixelStorei);
+    fFunctions.fPopGroupMarker = bind_to_member(this, &GrGLTestInterface::popGroupMarker);
+    fFunctions.fPushGroupMarker = bind_to_member(this, &GrGLTestInterface::pushGroupMarker);
+    fFunctions.fQueryCounter = bind_to_member(this, &GrGLTestInterface::queryCounter);
+    fFunctions.fRasterSamples = bind_to_member(this, &GrGLTestInterface::rasterSamples);
+    fFunctions.fReadBuffer = bind_to_member(this, &GrGLTestInterface::readBuffer);
+    fFunctions.fReadPixels = bind_to_member(this, &GrGLTestInterface::readPixels);
+    fFunctions.fRenderbufferStorage = bind_to_member(this, &GrGLTestInterface::renderbufferStorage);
+    fFunctions.fRenderbufferStorageMultisample = bind_to_member(this, &GrGLTestInterface::renderbufferStorageMultisample);
+    fFunctions.fResolveMultisampleFramebuffer = bind_to_member(this, &GrGLTestInterface::resolveMultisampleFramebuffer);
+    fFunctions.fScissor = bind_to_member(this, &GrGLTestInterface::scissor);
+    fFunctions.fBindUniformLocation = bind_to_member(this, &GrGLTestInterface::bindUniformLocation);
+    fFunctions.fShaderSource = bind_to_member(this, &GrGLTestInterface::shaderSource);
+    fFunctions.fStencilFunc = bind_to_member(this, &GrGLTestInterface::stencilFunc);
+    fFunctions.fStencilFuncSeparate = bind_to_member(this, &GrGLTestInterface::stencilFuncSeparate);
+    fFunctions.fStencilMask = bind_to_member(this, &GrGLTestInterface::stencilMask);
+    fFunctions.fStencilMaskSeparate = bind_to_member(this, &GrGLTestInterface::stencilMaskSeparate);
+    fFunctions.fStencilOp = bind_to_member(this, &GrGLTestInterface::stencilOp);
+    fFunctions.fStencilOpSeparate = bind_to_member(this, &GrGLTestInterface::stencilOpSeparate);
+    fFunctions.fTexBuffer = bind_to_member(this, &GrGLTestInterface::texBuffer);
+    fFunctions.fTexImage2D = bind_to_member(this, &GrGLTestInterface::texImage2D);
+    fFunctions.fTexParameteri = bind_to_member(this, &GrGLTestInterface::texParameteri);
+    fFunctions.fTexParameteriv = bind_to_member(this, &GrGLTestInterface::texParameteriv);
+    fFunctions.fTexStorage2D = bind_to_member(this, &GrGLTestInterface::texStorage2D);
+    fFunctions.fDiscardFramebuffer = bind_to_member(this, &GrGLTestInterface::discardFramebuffer);
+    fFunctions.fTexSubImage2D = bind_to_member(this, &GrGLTestInterface::texSubImage2D);
+    fFunctions.fTextureBarrier = bind_to_member(this, &GrGLTestInterface::textureBarrier);
+    fFunctions.fUniform1f = bind_to_member(this, &GrGLTestInterface::uniform1f);
+    fFunctions.fUniform1i = bind_to_member(this, &GrGLTestInterface::uniform1i);
+    fFunctions.fUniform1fv = bind_to_member(this, &GrGLTestInterface::uniform1fv);
+    fFunctions.fUniform1iv = bind_to_member(this, &GrGLTestInterface::uniform1iv);
+    fFunctions.fUniform2f = bind_to_member(this, &GrGLTestInterface::uniform2f);
+    fFunctions.fUniform2i = bind_to_member(this, &GrGLTestInterface::uniform2i);
+    fFunctions.fUniform2fv = bind_to_member(this, &GrGLTestInterface::uniform2fv);
+    fFunctions.fUniform2iv = bind_to_member(this, &GrGLTestInterface::uniform2iv);
+    fFunctions.fUniform3f = bind_to_member(this, &GrGLTestInterface::uniform3f);
+    fFunctions.fUniform3i = bind_to_member(this, &GrGLTestInterface::uniform3i);
+    fFunctions.fUniform3fv = bind_to_member(this, &GrGLTestInterface::uniform3fv);
+    fFunctions.fUniform3iv = bind_to_member(this, &GrGLTestInterface::uniform3iv);
+    fFunctions.fUniform4f = bind_to_member(this, &GrGLTestInterface::uniform4f);
+    fFunctions.fUniform4i = bind_to_member(this, &GrGLTestInterface::uniform4i);
+    fFunctions.fUniform4fv = bind_to_member(this, &GrGLTestInterface::uniform4fv);
+    fFunctions.fUniform4iv = bind_to_member(this, &GrGLTestInterface::uniform4iv);
+    fFunctions.fUniformMatrix2fv = bind_to_member(this, &GrGLTestInterface::uniformMatrix2fv);
+    fFunctions.fUniformMatrix3fv = bind_to_member(this, &GrGLTestInterface::uniformMatrix3fv);
+    fFunctions.fUniformMatrix4fv = bind_to_member(this, &GrGLTestInterface::uniformMatrix4fv);
+    fFunctions.fUnmapBuffer = bind_to_member(this, &GrGLTestInterface::unmapBuffer);
+    fFunctions.fUnmapBufferSubData = bind_to_member(this, &GrGLTestInterface::unmapBufferSubData);
+    fFunctions.fUnmapTexSubImage2D = bind_to_member(this, &GrGLTestInterface::unmapTexSubImage2D);
+    fFunctions.fUseProgram = bind_to_member(this, &GrGLTestInterface::useProgram);
+    fFunctions.fVertexAttrib1f = bind_to_member(this, &GrGLTestInterface::vertexAttrib1f);
+    fFunctions.fVertexAttrib2fv = bind_to_member(this, &GrGLTestInterface::vertexAttrib2fv);
+    fFunctions.fVertexAttrib3fv = bind_to_member(this, &GrGLTestInterface::vertexAttrib3fv);
+    fFunctions.fVertexAttrib4fv = bind_to_member(this, &GrGLTestInterface::vertexAttrib4fv);
+    fFunctions.fVertexAttribDivisor = bind_to_member(this, &GrGLTestInterface::vertexAttribDivisor);
+    fFunctions.fVertexAttribIPointer = bind_to_member(this, &GrGLTestInterface::vertexAttribIPointer);
+    fFunctions.fVertexAttribPointer = bind_to_member(this, &GrGLTestInterface::vertexAttribPointer);
+    fFunctions.fViewport = bind_to_member(this, &GrGLTestInterface::viewport);
+    fFunctions.fMatrixLoadf = bind_to_member(this, &GrGLTestInterface::matrixLoadf);
+    fFunctions.fMatrixLoadIdentity = bind_to_member(this, &GrGLTestInterface::matrixLoadIdentity);
+    fFunctions.fPathCommands = bind_to_member(this, &GrGLTestInterface::pathCommands);
+    fFunctions.fPathParameteri = bind_to_member(this, &GrGLTestInterface::pathParameteri);
+    fFunctions.fPathParameterf = bind_to_member(this, &GrGLTestInterface::pathParameterf);
+    fFunctions.fGenPaths = bind_to_member(this, &GrGLTestInterface::genPaths);
+    fFunctions.fDeletePaths = bind_to_member(this, &GrGLTestInterface::deletePaths);
+    fFunctions.fIsPath = bind_to_member(this, &GrGLTestInterface::isPath);
+    fFunctions.fPathStencilFunc = bind_to_member(this, &GrGLTestInterface::pathStencilFunc);
+    fFunctions.fStencilFillPath = bind_to_member(this, &GrGLTestInterface::stencilFillPath);
+    fFunctions.fStencilStrokePath = bind_to_member(this, &GrGLTestInterface::stencilStrokePath);
+    fFunctions.fStencilFillPathInstanced = bind_to_member(this, &GrGLTestInterface::stencilFillPathInstanced);
+    fFunctions.fStencilStrokePathInstanced = bind_to_member(this, &GrGLTestInterface::stencilStrokePathInstanced);
+    fFunctions.fCoverFillPath = bind_to_member(this, &GrGLTestInterface::coverFillPath);
+    fFunctions.fCoverStrokePath = bind_to_member(this, &GrGLTestInterface::coverStrokePath);
+    fFunctions.fCoverFillPathInstanced = bind_to_member(this, &GrGLTestInterface::coverFillPathInstanced);
+    fFunctions.fCoverStrokePathInstanced = bind_to_member(this, &GrGLTestInterface::coverStrokePathInstanced);
+    fFunctions.fStencilThenCoverFillPath = bind_to_member(this, &GrGLTestInterface::stencilThenCoverFillPath);
+    fFunctions.fStencilThenCoverStrokePath = bind_to_member(this, &GrGLTestInterface::stencilThenCoverStrokePath);
+    fFunctions.fStencilThenCoverFillPathInstanced = bind_to_member(this, &GrGLTestInterface::stencilThenCoverFillPathInstanced);
+    fFunctions.fStencilThenCoverStrokePathInstanced = bind_to_member(this, &GrGLTestInterface::stencilThenCoverStrokePathInstanced);
+    fFunctions.fProgramPathFragmentInputGen = bind_to_member(this, &GrGLTestInterface::programPathFragmentInputGen);
+    fFunctions.fBindFragmentInputLocation = bind_to_member(this, &GrGLTestInterface::bindFragmentInputLocation);
+    fFunctions.fGetProgramResourceLocation = bind_to_member(this, &GrGLTestInterface::getProgramResourceLocation);
+    fFunctions.fCoverageModulation = bind_to_member(this, &GrGLTestInterface::coverageModulation);
+    fFunctions.fMultiDrawArraysIndirect = bind_to_member(this, &GrGLTestInterface::multiDrawArraysIndirect);
+    fFunctions.fMultiDrawElementsIndirect = bind_to_member(this, &GrGLTestInterface::multiDrawElementsIndirect);
+    fFunctions.fGetTextureHandle = bind_to_member(this, &GrGLTestInterface::getTextureHandle);
+    fFunctions.fGetTextureSamplerHandle = bind_to_member(this, &GrGLTestInterface::getTextureSamplerHandle);
+    fFunctions.fMakeTextureHandleResident = bind_to_member(this, &GrGLTestInterface::makeTextureHandleResident);
+    fFunctions.fMakeTextureHandleNonResident = bind_to_member(this, &GrGLTestInterface::makeTextureHandleNonResident);
+    fFunctions.fGetImageHandle = bind_to_member(this, &GrGLTestInterface::getImageHandle);
+    fFunctions.fMakeImageHandleResident = bind_to_member(this, &GrGLTestInterface::makeImageHandleResident);
+    fFunctions.fMakeImageHandleNonResident = bind_to_member(this, &GrGLTestInterface::makeImageHandleNonResident);
+    fFunctions.fIsTextureHandleResident = bind_to_member(this, &GrGLTestInterface::isTextureHandleResident);
+    fFunctions.fIsImageHandleResident = bind_to_member(this, &GrGLTestInterface::isImageHandleResident);
+    fFunctions.fUniformHandleui64 = bind_to_member(this, &GrGLTestInterface::uniformHandleui64);
+    fFunctions.fUniformHandleui64v = bind_to_member(this, &GrGLTestInterface::uniformHandleui64v);
+    fFunctions.fProgramUniformHandleui64 = bind_to_member(this, &GrGLTestInterface::programUniformHandleui64);
+    fFunctions.fProgramUniformHandleui64v = bind_to_member(this, &GrGLTestInterface::programUniformHandleui64v);
+    fFunctions.fTextureParameteri = bind_to_member(this, &GrGLTestInterface::textureParameteri);
+    fFunctions.fTextureParameteriv = bind_to_member(this, &GrGLTestInterface::textureParameteriv);
+    fFunctions.fTextureParameterf = bind_to_member(this, &GrGLTestInterface::textureParameterf);
+    fFunctions.fTextureParameterfv = bind_to_member(this, &GrGLTestInterface::textureParameterfv);
+    fFunctions.fTextureImage1D = bind_to_member(this, &GrGLTestInterface::textureImage1D);
+    fFunctions.fTextureImage2D = bind_to_member(this, &GrGLTestInterface::textureImage2D);
+    fFunctions.fTextureSubImage1D = bind_to_member(this, &GrGLTestInterface::textureSubImage1D);
+    fFunctions.fTextureSubImage2D = bind_to_member(this, &GrGLTestInterface::textureSubImage2D);
+    fFunctions.fCopyTextureImage1D = bind_to_member(this, &GrGLTestInterface::copyTextureImage1D);
+    fFunctions.fCopyTextureImage2D = bind_to_member(this, &GrGLTestInterface::copyTextureImage2D);
+    fFunctions.fCopyTextureSubImage1D = bind_to_member(this, &GrGLTestInterface::copyTextureSubImage1D);
+    fFunctions.fCopyTextureSubImage2D = bind_to_member(this, &GrGLTestInterface::copyTextureSubImage2D);
+    fFunctions.fGetTextureImage = bind_to_member(this, &GrGLTestInterface::getTextureImage);
+    fFunctions.fGetTextureParameterfv = bind_to_member(this, &GrGLTestInterface::getTextureParameterfv);
+    fFunctions.fGetTextureParameteriv = bind_to_member(this, &GrGLTestInterface::getTextureParameteriv);
+    fFunctions.fGetTextureLevelParameterfv = bind_to_member(this, &GrGLTestInterface::getTextureLevelParameterfv);
+    fFunctions.fGetTextureLevelParameteriv = bind_to_member(this, &GrGLTestInterface::getTextureLevelParameteriv);
+    fFunctions.fTextureImage3D = bind_to_member(this, &GrGLTestInterface::textureImage3D);
+    fFunctions.fTextureSubImage3D = bind_to_member(this, &GrGLTestInterface::textureSubImage3D);
+    fFunctions.fCopyTextureSubImage3D = bind_to_member(this, &GrGLTestInterface::copyTextureSubImage3D);
+    fFunctions.fCompressedTextureImage3D = bind_to_member(this, &GrGLTestInterface::compressedTextureImage3D);
+    fFunctions.fCompressedTextureImage2D = bind_to_member(this, &GrGLTestInterface::compressedTextureImage2D);
+    fFunctions.fCompressedTextureImage1D = bind_to_member(this, &GrGLTestInterface::compressedTextureImage1D);
+    fFunctions.fCompressedTextureSubImage3D = bind_to_member(this, &GrGLTestInterface::compressedTextureSubImage3D);
+    fFunctions.fCompressedTextureSubImage2D = bind_to_member(this, &GrGLTestInterface::compressedTextureSubImage2D);
+    fFunctions.fCompressedTextureSubImage1D = bind_to_member(this, &GrGLTestInterface::compressedTextureSubImage1D);
+    fFunctions.fGetCompressedTextureImage = bind_to_member(this, &GrGLTestInterface::getCompressedTextureImage);
+    fFunctions.fNamedBufferData = bind_to_member(this, &GrGLTestInterface::namedBufferData);
+    fFunctions.fNamedBufferSubData = bind_to_member(this, &GrGLTestInterface::namedBufferSubData);
+    fFunctions.fMapNamedBuffer = bind_to_member(this, &GrGLTestInterface::mapNamedBuffer);
+    fFunctions.fUnmapNamedBuffer = bind_to_member(this, &GrGLTestInterface::unmapNamedBuffer);
+    fFunctions.fGetNamedBufferParameteriv = bind_to_member(this, &GrGLTestInterface::getNamedBufferParameteriv);
+    fFunctions.fGetNamedBufferPointerv = bind_to_member(this, &GrGLTestInterface::getNamedBufferPointerv);
+    fFunctions.fGetNamedBufferSubData = bind_to_member(this, &GrGLTestInterface::getNamedBufferSubData);
+    fFunctions.fProgramUniform1f = bind_to_member(this, &GrGLTestInterface::programUniform1f);
+    fFunctions.fProgramUniform2f = bind_to_member(this, &GrGLTestInterface::programUniform2f);
+    fFunctions.fProgramUniform3f = bind_to_member(this, &GrGLTestInterface::programUniform3f);
+    fFunctions.fProgramUniform4f = bind_to_member(this, &GrGLTestInterface::programUniform4f);
+    fFunctions.fProgramUniform1i = bind_to_member(this, &GrGLTestInterface::programUniform1i);
+    fFunctions.fProgramUniform2i = bind_to_member(this, &GrGLTestInterface::programUniform2i);
+    fFunctions.fProgramUniform3i = bind_to_member(this, &GrGLTestInterface::programUniform3i);
+    fFunctions.fProgramUniform4i = bind_to_member(this, &GrGLTestInterface::programUniform4i);
+    fFunctions.fProgramUniform1fv = bind_to_member(this, &GrGLTestInterface::programUniform1fv);
+    fFunctions.fProgramUniform2fv = bind_to_member(this, &GrGLTestInterface::programUniform2fv);
+    fFunctions.fProgramUniform3fv = bind_to_member(this, &GrGLTestInterface::programUniform3fv);
+    fFunctions.fProgramUniform4fv = bind_to_member(this, &GrGLTestInterface::programUniform4fv);
+    fFunctions.fProgramUniform1iv = bind_to_member(this, &GrGLTestInterface::programUniform1iv);
+    fFunctions.fProgramUniform2iv = bind_to_member(this, &GrGLTestInterface::programUniform2iv);
+    fFunctions.fProgramUniform3iv = bind_to_member(this, &GrGLTestInterface::programUniform3iv);
+    fFunctions.fProgramUniform4iv = bind_to_member(this, &GrGLTestInterface::programUniform4iv);
+    fFunctions.fProgramUniformMatrix2fv = bind_to_member(this, &GrGLTestInterface::programUniformMatrix2fv);
+    fFunctions.fProgramUniformMatrix3fv = bind_to_member(this, &GrGLTestInterface::programUniformMatrix3fv);
+    fFunctions.fProgramUniformMatrix4fv = bind_to_member(this, &GrGLTestInterface::programUniformMatrix4fv);
+    fFunctions.fProgramUniformMatrix2x3fv = bind_to_member(this, &GrGLTestInterface::programUniformMatrix2x3fv);
+    fFunctions.fProgramUniformMatrix3x2fv = bind_to_member(this, &GrGLTestInterface::programUniformMatrix3x2fv);
+    fFunctions.fProgramUniformMatrix2x4fv = bind_to_member(this, &GrGLTestInterface::programUniformMatrix2x4fv);
+    fFunctions.fProgramUniformMatrix4x2fv = bind_to_member(this, &GrGLTestInterface::programUniformMatrix4x2fv);
+    fFunctions.fProgramUniformMatrix3x4fv = bind_to_member(this, &GrGLTestInterface::programUniformMatrix3x4fv);
+    fFunctions.fProgramUniformMatrix4x3fv = bind_to_member(this, &GrGLTestInterface::programUniformMatrix4x3fv);
+    fFunctions.fNamedRenderbufferStorage = bind_to_member(this, &GrGLTestInterface::namedRenderbufferStorage);
+    fFunctions.fGetNamedRenderbufferParameteriv = bind_to_member(this, &GrGLTestInterface::getNamedRenderbufferParameteriv);
+    fFunctions.fNamedRenderbufferStorageMultisample = bind_to_member(this, &GrGLTestInterface::namedRenderbufferStorageMultisample);
+    fFunctions.fCheckNamedFramebufferStatus = bind_to_member(this, &GrGLTestInterface::checkNamedFramebufferStatus);
+    fFunctions.fNamedFramebufferTexture1D = bind_to_member(this, &GrGLTestInterface::namedFramebufferTexture1D);
+    fFunctions.fNamedFramebufferTexture2D = bind_to_member(this, &GrGLTestInterface::namedFramebufferTexture2D);
+    fFunctions.fNamedFramebufferTexture3D = bind_to_member(this, &GrGLTestInterface::namedFramebufferTexture3D);
+    fFunctions.fNamedFramebufferRenderbuffer = bind_to_member(this, &GrGLTestInterface::namedFramebufferRenderbuffer);
+    fFunctions.fGetNamedFramebufferAttachmentParameteriv = bind_to_member(this, &GrGLTestInterface::getNamedFramebufferAttachmentParameteriv);
+    fFunctions.fGenerateTextureMipmap = bind_to_member(this, &GrGLTestInterface::generateTextureMipmap);
+    fFunctions.fFramebufferDrawBuffer = bind_to_member(this, &GrGLTestInterface::framebufferDrawBuffer);
+    fFunctions.fFramebufferDrawBuffers = bind_to_member(this, &GrGLTestInterface::framebufferDrawBuffers);
+    fFunctions.fFramebufferReadBuffer = bind_to_member(this, &GrGLTestInterface::framebufferReadBuffer);
+    fFunctions.fGetFramebufferParameteriv = bind_to_member(this, &GrGLTestInterface::getFramebufferParameteriv);
+    fFunctions.fNamedCopyBufferSubData = bind_to_member(this, &GrGLTestInterface::namedCopyBufferSubData);
+    fFunctions.fVertexArrayVertexOffset = bind_to_member(this, &GrGLTestInterface::vertexArrayVertexOffset);
+    fFunctions.fVertexArrayColorOffset = bind_to_member(this, &GrGLTestInterface::vertexArrayColorOffset);
+    fFunctions.fVertexArrayEdgeFlagOffset = bind_to_member(this, &GrGLTestInterface::vertexArrayEdgeFlagOffset);
+    fFunctions.fVertexArrayIndexOffset = bind_to_member(this, &GrGLTestInterface::vertexArrayIndexOffset);
+    fFunctions.fVertexArrayNormalOffset = bind_to_member(this, &GrGLTestInterface::vertexArrayNormalOffset);
+    fFunctions.fVertexArrayTexCoordOffset = bind_to_member(this, &GrGLTestInterface::vertexArrayTexCoordOffset);
+    fFunctions.fVertexArrayMultiTexCoordOffset = bind_to_member(this, &GrGLTestInterface::vertexArrayMultiTexCoordOffset);
+    fFunctions.fVertexArrayFogCoordOffset = bind_to_member(this, &GrGLTestInterface::vertexArrayFogCoordOffset);
+    fFunctions.fVertexArraySecondaryColorOffset = bind_to_member(this, &GrGLTestInterface::vertexArraySecondaryColorOffset);
+    fFunctions.fVertexArrayVertexAttribOffset = bind_to_member(this, &GrGLTestInterface::vertexArrayVertexAttribOffset);
+    fFunctions.fVertexArrayVertexAttribIOffset = bind_to_member(this, &GrGLTestInterface::vertexArrayVertexAttribIOffset);
+    fFunctions.fEnableVertexArray = bind_to_member(this, &GrGLTestInterface::enableVertexArray);
+    fFunctions.fDisableVertexArray = bind_to_member(this, &GrGLTestInterface::disableVertexArray);
+    fFunctions.fEnableVertexArrayAttrib = bind_to_member(this, &GrGLTestInterface::enableVertexArrayAttrib);
+    fFunctions.fDisableVertexArrayAttrib = bind_to_member(this, &GrGLTestInterface::disableVertexArrayAttrib);
+    fFunctions.fGetVertexArrayIntegerv = bind_to_member(this, &GrGLTestInterface::getVertexArrayIntegerv);
+    fFunctions.fGetVertexArrayPointerv = bind_to_member(this, &GrGLTestInterface::getVertexArrayPointerv);
+    fFunctions.fGetVertexArrayIntegeri_v = bind_to_member(this, &GrGLTestInterface::getVertexArrayIntegeri_v);
+    fFunctions.fGetVertexArrayPointeri_v = bind_to_member(this, &GrGLTestInterface::getVertexArrayPointeri_v);
+    fFunctions.fMapNamedBufferRange = bind_to_member(this, &GrGLTestInterface::mapNamedBufferRange);
+    fFunctions.fFlushMappedNamedBufferRange = bind_to_member(this, &GrGLTestInterface::flushMappedNamedBufferRange);
+    fFunctions.fTextureBuffer = bind_to_member(this, &GrGLTestInterface::textureBuffer);
+    fFunctions.fDebugMessageControl = bind_to_member(this, &GrGLTestInterface::debugMessageControl);
+    fFunctions.fDebugMessageInsert = bind_to_member(this, &GrGLTestInterface::debugMessageInsert);
+    fFunctions.fDebugMessageCallback = bind_to_member(this, &GrGLTestInterface::debugMessageCallback);
+    fFunctions.fGetDebugMessageLog = bind_to_member(this, &GrGLTestInterface::getDebugMessageLog);
+    fFunctions.fPushDebugGroup = bind_to_member(this, &GrGLTestInterface::pushDebugGroup);
+    fFunctions.fPopDebugGroup = bind_to_member(this, &GrGLTestInterface::popDebugGroup);
+    fFunctions.fObjectLabel = bind_to_member(this, &GrGLTestInterface::objectLabel);
+}
diff --git a/src/gpu/gl/GrGLTestInterface.h b/src/gpu/gl/GrGLTestInterface.h
new file mode 100644
index 0000000000..f8c5801a7f
--- /dev/null
+++ b/src/gpu/gl/GrGLTestInterface.h
@@ -0,0 +1,332 @@
+/*
+ * Copyright 2016 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+
+#ifndef GrGLTestInterface_DEFINED
+#define GrGLTestInterface_DEFINED
+
+#include "gl/GrGLInterface.h"
+#include "GrGLDefines.h"
+
+class GrGLTestInterface : public GrGLInterface {
+public:
+    virtual GrGLvoid activeTexture(GrGLenum texture) {}
+    virtual GrGLvoid attachShader(GrGLuint program, GrGLuint shader) {}
+    virtual GrGLvoid beginQuery(GrGLenum target, GrGLuint id) {}
+    virtual GrGLvoid bindAttribLocation(GrGLuint program, GrGLuint index, const char* name) {}
+    virtual GrGLvoid bindBuffer(GrGLenum target, GrGLuint buffer) {}
+    virtual GrGLvoid bindFramebuffer(GrGLenum target, GrGLuint framebuffer) {}
+    virtual GrGLvoid bindRenderbuffer(GrGLenum target, GrGLuint renderbuffer) {}
+    virtual GrGLvoid bindTexture(GrGLenum target, GrGLuint texture) {}
+    virtual GrGLvoid bindFragDataLocation(GrGLuint program, GrGLuint colorNumber, const GrGLchar* name) {}
+    virtual GrGLvoid bindFragDataLocationIndexed(GrGLuint program, GrGLuint colorNumber, GrGLuint index, const GrGLchar * name) {}
+    virtual GrGLvoid bindVertexArray(GrGLuint array) {}
+    virtual GrGLvoid blendBarrier() {}
+    virtual GrGLvoid blendColor(GrGLclampf red, GrGLclampf green, GrGLclampf blue, GrGLclampf alpha) {}
+    virtual GrGLvoid blendEquation(GrGLenum mode) {}
+    virtual GrGLvoid blendFunc(GrGLenum sfactor, GrGLenum dfactor) {}
+    virtual GrGLvoid blitFramebuffer(GrGLint srcX0, GrGLint srcY0, GrGLint srcX1, GrGLint srcY1, GrGLint dstX0, GrGLint dstY0, GrGLint dstX1, GrGLint dstY1, GrGLbitfield mask, GrGLenum filter) {}
+    virtual GrGLvoid bufferData(GrGLenum target, GrGLsizeiptr size, const GrGLvoid* data, GrGLenum usage) {}
+    virtual GrGLvoid bufferSubData(GrGLenum target, GrGLintptr offset, GrGLsizeiptr size, const GrGLvoid* data) {}
+    virtual GrGLenum checkFramebufferStatus(GrGLenum target) { return GR_GL_FRAMEBUFFER_COMPLETE; }
+    virtual GrGLvoid clear(GrGLbitfield mask) {}
+    virtual GrGLvoid clearColor(GrGLclampf red, GrGLclampf green, GrGLclampf blue, GrGLclampf alpha) {}
+    virtual GrGLvoid clearStencil(GrGLint s) {}
+    virtual GrGLvoid colorMask(GrGLboolean red, GrGLboolean green, GrGLboolean blue, GrGLboolean alpha) {}
+    virtual GrGLvoid compileShader(GrGLuint shader) {}
+    virtual GrGLvoid compressedTexImage2D(GrGLenum target, GrGLint level, GrGLenum internalformat, GrGLsizei width, GrGLsizei height, GrGLint border, GrGLsizei imageSize, const GrGLvoid* data) {}
+    virtual GrGLvoid compressedTexSubImage2D(GrGLenum target, GrGLint level, GrGLint xoffset, GrGLint yoffset, GrGLsizei width, GrGLsizei height, GrGLenum format, GrGLsizei imageSize, const GrGLvoid* data) {}
+    virtual GrGLvoid copyTexSubImage2D(GrGLenum target, GrGLint level, GrGLint xoffset, GrGLint yoffset, GrGLint x, GrGLint y, GrGLsizei width, GrGLsizei height) {}
+    virtual GrGLuint createProgram() { return 0; }
+    virtual GrGLuint createShader(GrGLenum type) { return 0; }
+    virtual GrGLvoid cullFace(GrGLenum mode) {}
+    virtual GrGLvoid deleteBuffers(GrGLsizei n, const GrGLuint* buffers) {}
+    virtual GrGLvoid deleteFramebuffers(GrGLsizei n, const GrGLuint *framebuffers) {}
+    virtual GrGLvoid deleteProgram(GrGLuint program) {}
+    virtual GrGLvoid deleteQueries(GrGLsizei n, const GrGLuint *ids) {}
+    virtual GrGLvoid deleteRenderbuffers(GrGLsizei n, const GrGLuint *renderbuffers) {}
+    virtual GrGLvoid deleteShader(GrGLuint shader) {}
+    virtual GrGLvoid deleteTextures(GrGLsizei n, const GrGLuint* textures) {}
+    virtual GrGLvoid deleteVertexArrays(GrGLsizei n, const GrGLuint *arrays) {}
+    virtual GrGLvoid depthMask(GrGLboolean flag) {}
+    virtual GrGLvoid disable(GrGLenum cap) {}
+    virtual GrGLvoid disableVertexAttribArray(GrGLuint index) {}
+    virtual GrGLvoid drawArrays(GrGLenum mode, GrGLint first, GrGLsizei count) {}
+    virtual GrGLvoid drawArraysInstanced(GrGLenum mode, GrGLint first, GrGLsizei count, GrGLsizei primcount) {}
+    virtual GrGLvoid drawArraysIndirect(GrGLenum mode, GrGLvoid* indirect) {}
+    virtual GrGLvoid drawBuffer(GrGLenum mode) {}
+    virtual GrGLvoid drawBuffers(GrGLsizei n, const GrGLenum* bufs) {}
+    virtual GrGLvoid drawElements(GrGLenum mode, GrGLsizei count, GrGLenum type, const GrGLvoid* indices) {}
+    virtual GrGLvoid drawElementsInstanced(GrGLenum mode, GrGLsizei count, GrGLenum type, const GrGLvoid *indices, GrGLsizei primcount) {}
+    virtual GrGLvoid drawElementsIndirect(GrGLenum mode, GrGLenum type, GrGLvoid* indirect) {}
+    virtual GrGLvoid enable(GrGLenum cap) {}
+    virtual GrGLvoid enableVertexAttribArray(GrGLuint index) {}
+    virtual GrGLvoid endQuery(GrGLenum target) {}
+    virtual GrGLvoid finish() {}
+    virtual GrGLvoid flush() {}
+    virtual GrGLvoid flushMappedBufferRange(GrGLenum target, GrGLintptr offset, GrGLsizeiptr length) {}
+    virtual GrGLvoid framebufferRenderbuffer(GrGLenum target, GrGLenum attachment, GrGLenum renderbuffertarget, GrGLuint renderbuffer) {}
+    virtual GrGLvoid framebufferTexture2D(GrGLenum target, GrGLenum attachment, GrGLenum textarget, GrGLuint texture, GrGLint level) {}
+    virtual GrGLvoid framebufferTexture2DMultisample(GrGLenum target, GrGLenum attachment, GrGLenum textarget, GrGLuint texture, GrGLint level, GrGLsizei samples) {}
+    virtual GrGLvoid frontFace(GrGLenum mode) {}
+    virtual GrGLvoid genBuffers(GrGLsizei n, GrGLuint* buffers) {}
+    virtual GrGLvoid genFramebuffers(GrGLsizei n, GrGLuint *framebuffers) {}
+    virtual GrGLvoid generateMipmap(GrGLenum target) {}
+    virtual GrGLvoid genQueries(GrGLsizei n, GrGLuint *ids) {}
+    virtual GrGLvoid genRenderbuffers(GrGLsizei n, GrGLuint *renderbuffers) {}
+    virtual GrGLvoid genTextures(GrGLsizei n, GrGLuint* textures) {}
+    virtual GrGLvoid genVertexArrays(GrGLsizei n, GrGLuint *arrays) {}
+    virtual GrGLvoid getBufferParameteriv(GrGLenum target, GrGLenum pname, GrGLint* params) {}
+    virtual GrGLenum getError() { return GR_GL_NO_ERROR; }
+    virtual GrGLvoid getFramebufferAttachmentParameteriv(GrGLenum target, GrGLenum attachment, GrGLenum pname, GrGLint* params) {}
+    virtual GrGLvoid getIntegerv(GrGLenum pname, GrGLint* params) {}
+    virtual GrGLvoid getMultisamplefv(GrGLenum pname, GrGLuint index, GrGLfloat* val) {}
+    virtual GrGLvoid getProgramInfoLog(GrGLuint program, GrGLsizei bufsize, GrGLsizei* length, char* infolog) {}
+    virtual GrGLvoid getProgramiv(GrGLuint program, GrGLenum pname, GrGLint* params) {}
+    virtual GrGLvoid getQueryiv(GrGLenum GLtarget, GrGLenum pname, GrGLint *params) {}
+    virtual GrGLvoid getQueryObjecti64v(GrGLuint id, GrGLenum pname, GrGLint64 *params) {}
+    virtual GrGLvoid getQueryObjectiv(GrGLuint id, GrGLenum pname, GrGLint *params) {}
+    virtual GrGLvoid getQueryObjectui64v(GrGLuint id, GrGLenum pname, GrGLuint64 *params) {}
+    virtual GrGLvoid getQueryObjectuiv(GrGLuint id, GrGLenum pname, GrGLuint *params) {}
+    virtual GrGLvoid getRenderbufferParameteriv(GrGLenum target, GrGLenum pname, GrGLint* params) {}
+    virtual GrGLvoid getShaderInfoLog(GrGLuint shader, GrGLsizei bufsize, GrGLsizei* length, char* infolog) {}
+    virtual GrGLvoid getShaderiv(GrGLuint shader, GrGLenum pname, GrGLint* params) {}
+    virtual GrGLvoid getShaderPrecisionFormat(GrGLenum shadertype, GrGLenum precisiontype, GrGLint *range, GrGLint *precision) {}
+    virtual const GrGLubyte*  getString(GrGLenum name) { return nullptr; }
+    virtual const GrGLubyte* getStringi(GrGLenum name, GrGLuint index) { return nullptr; }
+    virtual GrGLvoid getTexLevelParameteriv(GrGLenum target, GrGLint level, GrGLenum pname, GrGLint* params) {}
+    virtual GrGLint getUniformLocation(GrGLuint program, const char* name) { return 0; }
+    virtual GrGLvoid insertEventMarker(GrGLsizei length, const char* marker) {}
+    virtual GrGLvoid invalidateBufferData(GrGLuint buffer) {}
+    virtual GrGLvoid invalidateBufferSubData(GrGLuint buffer, GrGLintptr offset, GrGLsizeiptr length) {}
+    virtual GrGLvoid invalidateFramebuffer(GrGLenum target, GrGLsizei numAttachments,  const GrGLenum *attachments) {}
+    virtual GrGLvoid invalidateSubFramebuffer(GrGLenum target, GrGLsizei numAttachments, const GrGLenum *attachments, GrGLint x, GrGLint y, GrGLsizei width, GrGLsizei height) {}
+    virtual GrGLvoid invalidateTexImage(GrGLuint texture, GrGLint level) {}
+    virtual GrGLvoid invalidateTexSubImage(GrGLuint texture, GrGLint level, GrGLint xoffset, GrGLint yoffset, GrGLint zoffset, GrGLsizei width, GrGLsizei height, GrGLsizei depth) {}
+    virtual GrGLboolean isTexture(GrGLuint texture) { return GR_GL_FALSE; }
+    virtual GrGLvoid lineWidth(GrGLfloat width) {}
+    virtual GrGLvoid linkProgram(GrGLuint program) {}
+    virtual GrGLvoid* mapBuffer(GrGLenum target, GrGLenum access) { return nullptr; }
+    virtual GrGLvoid* mapBufferRange(GrGLenum target, GrGLintptr offset, GrGLsizeiptr length, GrGLbitfield access) { return nullptr; }
+    virtual GrGLvoid* mapBufferSubData(GrGLuint target, GrGLintptr offset, GrGLsizeiptr size, GrGLenum access) { return nullptr; }
+    virtual GrGLvoid* mapTexSubImage2D(GrGLenum target, GrGLint level, GrGLint xoffset, GrGLint yoffset, GrGLsizei width, GrGLsizei height, GrGLenum format, GrGLenum type, GrGLenum access) { return nullptr; }
+    virtual GrGLvoid pixelStorei(GrGLenum pname, GrGLint param) {}
+    virtual GrGLvoid popGroupMarker() {}
+    virtual GrGLvoid pushGroupMarker(GrGLsizei length, const char* marker) {}
+    virtual GrGLvoid queryCounter(GrGLuint id, GrGLenum target) {}
+    virtual GrGLvoid rasterSamples(GrGLuint samples, GrGLboolean fixedsamplelocations) {}
+    virtual GrGLvoid readBuffer(GrGLenum src) {}
+    virtual GrGLvoid readPixels(GrGLint x, GrGLint y, GrGLsizei width, GrGLsizei height, GrGLenum format, GrGLenum type, GrGLvoid* pixels) {}
+    virtual GrGLvoid renderbufferStorage(GrGLenum target, GrGLenum internalformat, GrGLsizei width, GrGLsizei height) {}
+    virtual GrGLvoid renderbufferStorageMultisample(GrGLenum target, GrGLsizei samples, GrGLenum internalformat, GrGLsizei width, GrGLsizei height) {}
+    virtual GrGLvoid resolveMultisampleFramebuffer() {}
+    virtual GrGLvoid scissor(GrGLint x, GrGLint y, GrGLsizei width, GrGLsizei height) {}
+    virtual GrGLvoid bindUniformLocation(GrGLuint program, GrGLint location, const char* name) {}
+#if GR_GL_USE_NEW_SHADER_SOURCE_SIGNATURE
+    virtual GrGLvoid shaderSource(GrGLuint shader, GrGLsizei count, const char* const * str, const GrGLint* length) {}
+#else
+    virtual GrGLvoid shaderSource(GrGLuint shader, GrGLsizei count, const char** str, const GrGLint* length) {}
+#endif
+    virtual GrGLvoid stencilFunc(GrGLenum func, GrGLint ref, GrGLuint mask) {}
+    virtual GrGLvoid stencilFuncSeparate(GrGLenum face, GrGLenum func, GrGLint ref, GrGLuint mask) {}
+    virtual GrGLvoid stencilMask(GrGLuint mask) {}
+    virtual GrGLvoid stencilMaskSeparate(GrGLenum face, GrGLuint mask) {}
+    virtual GrGLvoid stencilOp(GrGLenum fail, GrGLenum zfail, GrGLenum zpass) {}
+    virtual GrGLvoid stencilOpSeparate(GrGLenum face, GrGLenum fail, GrGLenum zfail, GrGLenum zpass) {}
+    virtual GrGLvoid texBuffer(GrGLenum target, GrGLenum internalformat, GrGLuint buffer) {}
+    virtual GrGLvoid texImage2D(GrGLenum target, GrGLint level, GrGLint internalformat, GrGLsizei width, GrGLsizei height, GrGLint border, GrGLenum format, GrGLenum type, const GrGLvoid* pixels) {}
+    virtual GrGLvoid texParameteri(GrGLenum target, GrGLenum pname, GrGLint param) {}
+    virtual GrGLvoid texParameteriv(GrGLenum target, GrGLenum pname, const GrGLint* params) {}
+    virtual GrGLvoid texStorage2D(GrGLenum target, GrGLsizei levels, GrGLenum internalformat, GrGLsizei width, GrGLsizei height) {}
+    virtual GrGLvoid discardFramebuffer(GrGLenum target, GrGLsizei numAttachments, const GrGLenum* attachments) {}
+    virtual GrGLvoid texSubImage2D(GrGLenum target, GrGLint level, GrGLint xoffset, GrGLint yoffset, GrGLsizei width, GrGLsizei height, GrGLenum format, GrGLenum type, const GrGLvoid* pixels) {}
+    virtual GrGLvoid textureBarrier() {}
+    virtual GrGLvoid uniform1f(GrGLint location, GrGLfloat v0) {}
+    virtual GrGLvoid uniform1i(GrGLint location, GrGLint v0) {}
+    virtual GrGLvoid uniform1fv(GrGLint location, GrGLsizei count, const GrGLfloat* v) {}
+    virtual GrGLvoid uniform1iv(GrGLint location, GrGLsizei count, const GrGLint* v) {}
+    virtual GrGLvoid uniform2f(GrGLint location, GrGLfloat v0, GrGLfloat v1) {}
+    virtual GrGLvoid uniform2i(GrGLint location, GrGLint v0, GrGLint v1) {}
+    virtual GrGLvoid uniform2fv(GrGLint location, GrGLsizei count, const GrGLfloat* v) {}
+    virtual GrGLvoid uniform2iv(GrGLint location, GrGLsizei count, const GrGLint* v) {}
+    virtual GrGLvoid uniform3f(GrGLint location, GrGLfloat v0, GrGLfloat v1, GrGLfloat v2) {}
+    virtual GrGLvoid uniform3i(GrGLint location, GrGLint v0, GrGLint v1, GrGLint v2) {}
+    virtual GrGLvoid uniform3fv(GrGLint location, GrGLsizei count, const GrGLfloat* v) {}
+    virtual GrGLvoid uniform3iv(GrGLint location, GrGLsizei count, const GrGLint* v) {}
+    virtual GrGLvoid uniform4f(GrGLint location, GrGLfloat v0, GrGLfloat v1, GrGLfloat v2, GrGLfloat v3) {}
+    virtual GrGLvoid uniform4i(GrGLint location, GrGLint v0, GrGLint v1, GrGLint v2, GrGLint v3) {}
+    virtual GrGLvoid uniform4fv(GrGLint location, GrGLsizei count, const GrGLfloat* v) {}
+    virtual GrGLvoid uniform4iv(GrGLint location, GrGLsizei count, const GrGLint* v) {}
+    virtual GrGLvoid uniformMatrix2fv(GrGLint location, GrGLsizei count, GrGLboolean transpose, const GrGLfloat* value) {}
+    virtual GrGLvoid uniformMatrix3fv(GrGLint location, GrGLsizei count, GrGLboolean transpose, const GrGLfloat* value) {}
+    virtual GrGLvoid uniformMatrix4fv(GrGLint location, GrGLsizei count, GrGLboolean transpose, const GrGLfloat* value) {}
+    virtual GrGLboolean unmapBuffer(GrGLenum target) { return GR_GL_TRUE; }
+    virtual GrGLvoid unmapBufferSubData(const GrGLvoid* mem) {}
+    virtual GrGLvoid unmapTexSubImage2D(const GrGLvoid* mem) {}
+    virtual GrGLvoid useProgram(GrGLuint program) {}
+    virtual GrGLvoid vertexAttrib1f(GrGLuint indx, const GrGLfloat value) {}
+    virtual GrGLvoid vertexAttrib2fv(GrGLuint indx, const GrGLfloat* values) {}
+    virtual GrGLvoid vertexAttrib3fv(GrGLuint indx, const GrGLfloat* values) {}
+    virtual GrGLvoid vertexAttrib4fv(GrGLuint indx, const GrGLfloat* values) {}
+    virtual GrGLvoid vertexAttribDivisor(GrGLuint index, GrGLuint divisor) {}
+    virtual GrGLvoid vertexAttribIPointer(GrGLuint indx, GrGLint size, GrGLenum type, GrGLsizei stride, const GrGLvoid* ptr) {}
+    virtual GrGLvoid vertexAttribPointer(GrGLuint indx, GrGLint size, GrGLenum type, GrGLboolean normalized, GrGLsizei stride, const GrGLvoid* ptr) {}
+    virtual GrGLvoid viewport(GrGLint x, GrGLint y, GrGLsizei width, GrGLsizei height) {}
+    virtual GrGLvoid matrixLoadf(GrGLenum matrixMode, const GrGLfloat* m) {}
+    virtual GrGLvoid matrixLoadIdentity(GrGLenum) {}
+    virtual GrGLvoid pathCommands(GrGLuint path, GrGLsizei numCommands, const GrGLubyte *commands, GrGLsizei numCoords, GrGLenum coordType, const GrGLvoid *coords) {}
+    virtual GrGLvoid pathParameteri(GrGLuint path, GrGLenum pname, GrGLint value) {}
+    virtual GrGLvoid pathParameterf(GrGLuint path, GrGLenum pname, GrGLfloat value) {}
+    virtual GrGLuint genPaths(GrGLsizei range) { return 0; }
+    virtual GrGLvoid deletePaths(GrGLuint path, GrGLsizei range) {}
+    virtual GrGLboolean isPath(GrGLuint path) { return true; }
+    virtual GrGLvoid pathStencilFunc(GrGLenum func, GrGLint ref, GrGLuint mask) {}
+    virtual GrGLvoid stencilFillPath(GrGLuint path, GrGLenum fillMode, GrGLuint mask) {}
+    virtual GrGLvoid stencilStrokePath(GrGLuint path, GrGLint reference, GrGLuint mask) {}
+    virtual GrGLvoid stencilFillPathInstanced(GrGLsizei numPaths, GrGLenum pathNameType, const GrGLvoid *paths, GrGLuint pathBase, GrGLenum fillMode, GrGLuint mask, GrGLenum transformType, const GrGLfloat *transformValues) {}
+    virtual GrGLvoid stencilStrokePathInstanced(GrGLsizei numPaths, GrGLenum pathNameType, const GrGLvoid *paths, GrGLuint pathBase, GrGLint reference, GrGLuint mask, GrGLenum transformType, const GrGLfloat *transformValues) {}
+    virtual GrGLvoid coverFillPath(GrGLuint path, GrGLenum coverMode) {}
+    virtual GrGLvoid coverStrokePath(GrGLuint name, GrGLenum coverMode) {}
+    virtual GrGLvoid coverFillPathInstanced(GrGLsizei numPaths, GrGLenum pathNameType, const GrGLvoid *paths, GrGLuint pathBase, GrGLenum coverMode, GrGLenum transformType, const GrGLfloat *transformValues) {}
+    virtual GrGLvoid coverStrokePathInstanced(GrGLsizei numPaths, GrGLenum pathNameType, const GrGLvoid *paths, GrGLuint pathBase, GrGLenum coverMode, GrGLenum transformType, const GrGLfloat* transformValues) {}
+    virtual GrGLvoid stencilThenCoverFillPath(GrGLuint path, GrGLenum fillMode, GrGLuint mask, GrGLenum coverMode) {}
+    virtual GrGLvoid stencilThenCoverStrokePath(GrGLuint path, GrGLint reference, GrGLuint mask, GrGLenum coverMode) {}
+    virtual GrGLvoid stencilThenCoverFillPathInstanced(GrGLsizei numPaths, GrGLenum pathNameType, const GrGLvoid *paths, GrGLuint pathBase, GrGLenum fillMode, GrGLuint mask, GrGLenum coverMode, GrGLenum transformType, const GrGLfloat *transformValues) {}
+    virtual GrGLvoid stencilThenCoverStrokePathInstanced(GrGLsizei numPaths, GrGLenum pathNameType, const GrGLvoid *paths, GrGLuint pathBase, GrGLint reference, GrGLuint mask, GrGLenum coverMode, GrGLenum transformType, const GrGLfloat *transformValues) {}
+    virtual GrGLvoid programPathFragmentInputGen(GrGLuint program, GrGLint location, GrGLenum genMode, GrGLint components,const GrGLfloat *coeffs) {}
+    virtual GrGLvoid bindFragmentInputLocation(GrGLuint program, GrGLint location, const GrGLchar* name) {}
+    virtual GrGLint getProgramResourceLocation(GrGLuint program, GrGLenum programInterface, const GrGLchar *name) { return 0; }
+    virtual GrGLvoid coverageModulation(GrGLenum components) {}
+    virtual GrGLvoid multiDrawArraysIndirect(GrGLenum mode, const GrGLvoid *indirect, GrGLsizei drawcount, GrGLsizei stride) {}
+    virtual GrGLvoid multiDrawElementsIndirect(GrGLenum mode, GrGLenum type, const GrGLvoid *indirect, GrGLsizei drawcount, GrGLsizei stride) {}
+    virtual GrGLuint64 getTextureHandle(GrGLuint texture) { return 0; }
+    virtual GrGLuint64 getTextureSamplerHandle(GrGLuint texture, GrGLuint sampler) { return 0; }
+    virtual GrGLvoid makeTextureHandleResident(GrGLuint64 handle) {}
+    virtual GrGLvoid makeTextureHandleNonResident(GrGLuint64 handle) {}
+    virtual GrGLuint64 getImageHandle(GrGLuint texture, GrGLint level, GrGLboolean layered, GrGLint layer, GrGLint format) { return 0; }
+    virtual GrGLvoid makeImageHandleResident(GrGLuint64 handle, GrGLenum access) {}
+    virtual GrGLvoid makeImageHandleNonResident(GrGLuint64 handle) {}
+    virtual GrGLboolean isTextureHandleResident(GrGLuint64 handle) { return GR_GL_FALSE; }
+    virtual GrGLboolean isImageHandleResident(GrGLuint64 handle) { return GR_GL_FALSE; }
+    virtual GrGLvoid uniformHandleui64(GrGLint location, GrGLuint64 v0) {}
+    virtual GrGLvoid uniformHandleui64v(GrGLint location, GrGLsizei count, const GrGLuint64 *value) {}
+    virtual GrGLvoid programUniformHandleui64(GrGLuint program, GrGLint location, GrGLuint64 v0) {}
+    virtual GrGLvoid programUniformHandleui64v(GrGLuint program, GrGLint location, GrGLsizei count, const GrGLuint64 *value) {}
+    virtual GrGLvoid textureParameteri(GrGLuint texture, GrGLenum target, GrGLenum pname, GrGLint param) {}
+    virtual GrGLvoid textureParameteriv(GrGLuint texture, GrGLenum target, GrGLenum pname, const GrGLint *param) {}
+    virtual GrGLvoid textureParameterf(GrGLuint texture, GrGLenum target, GrGLenum pname, float param) {}
+    virtual GrGLvoid textureParameterfv(GrGLuint texture, GrGLenum target, GrGLenum pname, const float *param) {}
+    virtual GrGLvoid textureImage1D(GrGLuint texture, GrGLenum target, GrGLint level, GrGLint GrGLinternalformat, GrGLsizei width, GrGLint border, GrGLenum format, GrGLenum type, const GrGLvoid *pixels) {}
+    virtual GrGLvoid textureImage2D(GrGLuint texture, GrGLenum target, GrGLint level, GrGLint GrGLinternalformat, GrGLsizei width, GrGLsizei height, GrGLint border, GrGLenum format, GrGLenum type, const GrGLvoid *pixels) {}
+    virtual GrGLvoid textureSubImage1D(GrGLuint texture, GrGLenum target, GrGLint level, GrGLint xoffset, GrGLsizei width, GrGLenum format, GrGLenum type, const GrGLvoid *pixels) {}
+    virtual GrGLvoid textureSubImage2D(GrGLuint texture, GrGLenum target, GrGLint level, GrGLint xoffset, GrGLint yoffset, GrGLsizei width, GrGLsizei height, GrGLenum format, GrGLenum type, const GrGLvoid *pixels) {}
+    virtual GrGLvoid copyTextureImage1D(GrGLuint texture, GrGLenum target, GrGLint level, GrGLenum GrGLinternalformat, GrGLint x, GrGLint y, GrGLsizei width, GrGLint border) {}
+    virtual GrGLvoid copyTextureImage2D(GrGLuint texture, GrGLenum target, GrGLint level, GrGLenum GrGLinternalformat, GrGLint x, GrGLint y, GrGLsizei width, GrGLsizei height, GrGLint border) {}
+    virtual GrGLvoid copyTextureSubImage1D(GrGLuint texture, GrGLenum target, GrGLint level, GrGLint xoffset, GrGLint x, GrGLint y, GrGLsizei width) {}
+    virtual GrGLvoid copyTextureSubImage2D(GrGLuint texture, GrGLenum target, GrGLint level, GrGLint xoffset, GrGLint yoffset, GrGLint x, GrGLint y, GrGLsizei width, GrGLsizei height) {}
+    virtual GrGLvoid getTextureImage(GrGLuint texture, GrGLenum target, GrGLint level, GrGLenum format, GrGLenum type, GrGLvoid *pixels) {}
+    virtual GrGLvoid getTextureParameterfv(GrGLuint texture, GrGLenum target, GrGLenum pname, float *params) {}
+    virtual GrGLvoid getTextureParameteriv(GrGLuint texture, GrGLenum target, GrGLenum pname, GrGLint *params) {}
+    virtual GrGLvoid getTextureLevelParameterfv(GrGLuint texture, GrGLenum target, GrGLint level, GrGLenum pname, float *params) {}
+    virtual GrGLvoid getTextureLevelParameteriv(GrGLuint texture, GrGLenum target, GrGLint level, GrGLenum pname, GrGLint *params) {}
+    virtual GrGLvoid textureImage3D(GrGLuint texture, GrGLenum target, GrGLint level, GrGLint GrGLinternalformat, GrGLsizei width, GrGLsizei height, GrGLsizei depth, GrGLint border, GrGLenum format, GrGLenum type, const GrGLvoid *pixels) {}
+    virtual GrGLvoid textureSubImage3D(GrGLuint texture, GrGLenum target, GrGLint level, GrGLint xoffset, GrGLint yoffset, GrGLint zoffset, GrGLsizei width, GrGLsizei height, GrGLsizei depth, GrGLenum format, GrGLenum type, const GrGLvoid *pixels) {}
+    virtual GrGLvoid copyTextureSubImage3D(GrGLuint texture, GrGLenum target, GrGLint level, GrGLint xoffset, GrGLint yoffset, GrGLint zoffset, GrGLint x, GrGLint y, GrGLsizei width, GrGLsizei height) {}
+    virtual GrGLvoid compressedTextureImage3D(GrGLuint texture, GrGLenum target, GrGLint level, GrGLenum GrGLinternalformat, GrGLsizei width, GrGLsizei height, GrGLsizei depth, GrGLint border, GrGLsizei imageSize, const GrGLvoid *data) {}
+    virtual GrGLvoid compressedTextureImage2D(GrGLuint texture, GrGLenum target, GrGLint level, GrGLenum GrGLinternalformat, GrGLsizei width, GrGLsizei height, GrGLint border, GrGLsizei imageSize, const GrGLvoid *data) {}
+    virtual GrGLvoid compressedTextureImage1D(GrGLuint texture, GrGLenum target, GrGLint level, GrGLenum GrGLinternalformat, GrGLsizei width, GrGLint border, GrGLsizei imageSize, const GrGLvoid *data) {}
+    virtual GrGLvoid compressedTextureSubImage3D(GrGLuint texture, GrGLenum target, GrGLint level, GrGLint xoffset, GrGLint yoffset, GrGLint zoffset, GrGLsizei width, GrGLsizei height, GrGLsizei depth, GrGLenum format, GrGLsizei imageSize, const GrGLvoid *data) {}
+    virtual GrGLvoid compressedTextureSubImage2D(GrGLuint texture, GrGLenum target, GrGLint level, GrGLint xoffset, GrGLint yoffset, GrGLsizei width, GrGLsizei height, GrGLenum format, GrGLsizei imageSize, const GrGLvoid *data) {}
+    virtual GrGLvoid compressedTextureSubImage1D(GrGLuint texture, GrGLenum target, GrGLint level, GrGLint xoffset, GrGLsizei width, GrGLenum format, GrGLsizei imageSize, const GrGLvoid *data) {}
+    virtual GrGLvoid getCompressedTextureImage(GrGLuint texture, GrGLenum target, GrGLint level, GrGLvoid *img) {}
+    virtual GrGLvoid namedBufferData(GrGLuint buffer, GrGLsizeiptr size, const GrGLvoid *data, GrGLenum usage) {}
+    virtual GrGLvoid namedBufferSubData(GrGLuint buffer, GrGLintptr offset, GrGLsizeiptr size, const GrGLvoid *data) {}
+    virtual GrGLvoid* mapNamedBuffer(GrGLuint buffer, GrGLenum access) { return nullptr; }
+    virtual GrGLboolean unmapNamedBuffer(GrGLuint buffer) { return GR_GL_FALSE; }
+    virtual GrGLvoid getNamedBufferParameteriv(GrGLuint buffer, GrGLenum pname, GrGLint *params) {}
+    virtual GrGLvoid getNamedBufferPointerv(GrGLuint buffer, GrGLenum pname, GrGLvoid* *params) {}
+    virtual GrGLvoid getNamedBufferSubData(GrGLuint buffer, GrGLintptr offset, GrGLsizeiptr size, GrGLvoid *data) {}
+    virtual GrGLvoid programUniform1f(GrGLuint program, GrGLint location, float v0) {}
+    virtual GrGLvoid programUniform2f(GrGLuint program, GrGLint location, float v0, float v1) {}
+    virtual GrGLvoid programUniform3f(GrGLuint program, GrGLint location, float v0, float v1, float v2) {}
+    virtual GrGLvoid programUniform4f(GrGLuint program, GrGLint location, float v0, float v1, float v2, float v3) {}
+    virtual GrGLvoid programUniform1i(GrGLuint program, GrGLint location, GrGLint v0) {}
+    virtual GrGLvoid programUniform2i(GrGLuint program, GrGLint location, GrGLint v0, GrGLint v1) {}
+    virtual GrGLvoid programUniform3i(GrGLuint program, GrGLint location, GrGLint v0, GrGLint v1, GrGLint v2) {}
+    virtual GrGLvoid programUniform4i(GrGLuint program, GrGLint location, GrGLint v0, GrGLint v1, GrGLint v2, GrGLint v3) {}
+    virtual GrGLvoid programUniform1fv(GrGLuint program, GrGLint location, GrGLsizei count, const float *value) {}
+    virtual GrGLvoid programUniform2fv(GrGLuint program, GrGLint location, GrGLsizei count, const float *value) {}
+    virtual GrGLvoid programUniform3fv(GrGLuint program, GrGLint location, GrGLsizei count, const float *value) {}
+    virtual GrGLvoid programUniform4fv(GrGLuint program, GrGLint location, GrGLsizei count, const float *value) {}
+    virtual GrGLvoid programUniform1iv(GrGLuint program, GrGLint location, GrGLsizei count, const GrGLint *value) {}
+    virtual GrGLvoid programUniform2iv(GrGLuint program, GrGLint location, GrGLsizei count, const GrGLint *value) {}
+    virtual GrGLvoid programUniform3iv(GrGLuint program, GrGLint location, GrGLsizei count, const GrGLint *value) {}
+    virtual GrGLvoid programUniform4iv(GrGLuint program, GrGLint location, GrGLsizei count, const GrGLint *value) {}
+    virtual GrGLvoid programUniformMatrix2fv(GrGLuint program, GrGLint location, GrGLsizei count, GrGLboolean transpose, const float *value) {}
+    virtual GrGLvoid programUniformMatrix3fv(GrGLuint program, GrGLint location, GrGLsizei count, GrGLboolean transpose, const float *value) {}
+    virtual GrGLvoid programUniformMatrix4fv(GrGLuint program, GrGLint location, GrGLsizei count, GrGLboolean transpose, const float *value) {}
+    virtual GrGLvoid programUniformMatrix2x3fv(GrGLuint program, GrGLint location, GrGLsizei count, GrGLboolean transpose, const float *value) {}
+    virtual GrGLvoid programUniformMatrix3x2fv(GrGLuint program, GrGLint location, GrGLsizei count, GrGLboolean transpose, const float *value) {}
+    virtual GrGLvoid programUniformMatrix2x4fv(GrGLuint program, GrGLint location, GrGLsizei count, GrGLboolean transpose, const float *value) {}
+    virtual GrGLvoid programUniformMatrix4x2fv(GrGLuint program, GrGLint location, GrGLsizei count, GrGLboolean transpose, const float *value) {}
+    virtual GrGLvoid programUniformMatrix3x4fv(GrGLuint program, GrGLint location, GrGLsizei count, GrGLboolean transpose, const float *value) {}
+    virtual GrGLvoid programUniformMatrix4x3fv(GrGLuint program, GrGLint location, GrGLsizei count, GrGLboolean transpose, const float *value) {}
+    virtual GrGLvoid namedRenderbufferStorage(GrGLuint renderbuffer, GrGLenum GrGLinternalformat, GrGLsizei width, GrGLsizei height) {}
+    virtual GrGLvoid getNamedRenderbufferParameteriv(GrGLuint renderbuffer, GrGLenum pname, GrGLint *params) {}
+    virtual GrGLvoid namedRenderbufferStorageMultisample(GrGLuint renderbuffer, GrGLsizei samples, GrGLenum GrGLinternalformat, GrGLsizei width, GrGLsizei height) {}
+    virtual GrGLenum checkNamedFramebufferStatus(GrGLuint framebuffer, GrGLenum target) { return GR_GL_FRAMEBUFFER_COMPLETE; }
+    virtual GrGLvoid namedFramebufferTexture1D(GrGLuint framebuffer, GrGLenum attachment, GrGLenum textarget, GrGLuint texture, GrGLint level) {}
+    virtual GrGLvoid namedFramebufferTexture2D(GrGLuint framebuffer, GrGLenum attachment, GrGLenum textarget, GrGLuint texture, GrGLint level) {}
+    virtual GrGLvoid namedFramebufferTexture3D(GrGLuint framebuffer, GrGLenum attachment, GrGLenum textarget, GrGLuint texture, GrGLint level, GrGLint zoffset) {}
+    virtual GrGLvoid namedFramebufferRenderbuffer(GrGLuint framebuffer, GrGLenum attachment, GrGLenum renderbuffertarget, GrGLuint renderbuffer) {}
+    virtual GrGLvoid getNamedFramebufferAttachmentParameteriv(GrGLuint framebuffer, GrGLenum attachment, GrGLenum pname, GrGLint *params) {}
+    virtual GrGLvoid generateTextureMipmap(GrGLuint texture, GrGLenum target) {}
+    virtual GrGLvoid framebufferDrawBuffer(GrGLuint framebuffer, GrGLenum mode) {}
+    virtual GrGLvoid framebufferDrawBuffers(GrGLuint framebuffer, GrGLsizei n, const GrGLenum *bufs) {}
+    virtual GrGLvoid framebufferReadBuffer(GrGLuint framebuffer, GrGLenum mode) {}
+    virtual GrGLvoid getFramebufferParameteriv(GrGLuint framebuffer, GrGLenum pname, GrGLint *param) {}
+    virtual GrGLvoid namedCopyBufferSubData(GrGLuint readBuffer, GrGLuint writeBuffer, GrGLintptr readOffset, GrGLintptr writeOffset, GrGLsizeiptr size) {}
+    virtual GrGLvoid vertexArrayVertexOffset(GrGLuint vaobj, GrGLuint buffer, GrGLint size, GrGLenum type, GrGLsizei stride, GrGLintptr offset) {}
+    virtual GrGLvoid vertexArrayColorOffset(GrGLuint vaobj, GrGLuint buffer, GrGLint size, GrGLenum type, GrGLsizei stride, GrGLintptr offset) {}
+    virtual GrGLvoid vertexArrayEdgeFlagOffset(GrGLuint vaobj, GrGLuint buffer, GrGLsizei stride, GrGLintptr offset) {}
+    virtual GrGLvoid vertexArrayIndexOffset(GrGLuint vaobj, GrGLuint buffer, GrGLenum type, GrGLsizei stride, GrGLintptr offset) {}
+    virtual GrGLvoid vertexArrayNormalOffset(GrGLuint vaobj, GrGLuint buffer, GrGLenum type, GrGLsizei stride, GrGLintptr offset) {}
+    virtual GrGLvoid vertexArrayTexCoordOffset(GrGLuint vaobj, GrGLuint buffer, GrGLint size, GrGLenum type, GrGLsizei stride, GrGLintptr offset) {}
+    virtual GrGLvoid vertexArrayMultiTexCoordOffset(GrGLuint vaobj, GrGLuint buffer, GrGLenum texunit, GrGLint size, GrGLenum type, GrGLsizei stride, GrGLintptr offset) {}
+    virtual GrGLvoid vertexArrayFogCoordOffset(GrGLuint vaobj, GrGLuint buffer, GrGLenum type, GrGLsizei stride, GrGLintptr offset) {}
+    virtual GrGLvoid vertexArraySecondaryColorOffset(GrGLuint vaobj, GrGLuint buffer, GrGLint size, GrGLenum type, GrGLsizei stride, GrGLintptr offset) {}
+    virtual GrGLvoid vertexArrayVertexAttribOffset(GrGLuint vaobj, GrGLuint buffer, GrGLuint index, GrGLint size, GrGLenum type, GrGLboolean normalized, GrGLsizei stride, GrGLintptr offset) {}
+    virtual GrGLvoid vertexArrayVertexAttribIOffset(GrGLuint vaobj, GrGLuint buffer, GrGLuint index, GrGLint size, GrGLenum type, GrGLsizei stride, GrGLintptr offset) {}
+    virtual GrGLvoid enableVertexArray(GrGLuint vaobj, GrGLenum array) {}
+    virtual GrGLvoid disableVertexArray(GrGLuint vaobj, GrGLenum array) {}
+    virtual GrGLvoid enableVertexArrayAttrib(GrGLuint vaobj, GrGLuint index) {}
+    virtual GrGLvoid disableVertexArrayAttrib(GrGLuint vaobj, GrGLuint index) {}
+    virtual GrGLvoid getVertexArrayIntegerv(GrGLuint vaobj, GrGLenum pname, GrGLint *param) {}
+    virtual GrGLvoid getVertexArrayPointerv(GrGLuint vaobj, GrGLenum pname, GrGLvoid **param) {}
+    virtual GrGLvoid getVertexArrayIntegeri_v(GrGLuint vaobj, GrGLuint index, GrGLenum pname, GrGLint *param) {}
+    virtual GrGLvoid getVertexArrayPointeri_v(GrGLuint vaobj, GrGLuint index, GrGLenum pname, GrGLvoid **param) {}
+    virtual GrGLvoid* mapNamedBufferRange(GrGLuint buffer, GrGLintptr offset, GrGLsizeiptr length, GrGLbitfield access) { return nullptr; }
+    virtual GrGLvoid flushMappedNamedBufferRange(GrGLuint buffer, GrGLintptr offset, GrGLsizeiptr length) {}
+    virtual GrGLvoid textureBuffer(GrGLuint texture, GrGLenum target, GrGLenum internalformat, GrGLuint buffer) {}
+    virtual GrGLvoid debugMessageControl(GrGLenum source, GrGLenum type, GrGLenum severity, GrGLsizei count, const GrGLuint* ids, GrGLboolean enabled) {}
+    virtual GrGLvoid debugMessageInsert(GrGLenum source, GrGLenum type, GrGLuint id, GrGLenum severity, GrGLsizei length,  const GrGLchar* buf) {}
+    virtual GrGLvoid debugMessageCallback(GRGLDEBUGPROC callback, const GrGLvoid* userParam) {}
+    virtual GrGLuint getDebugMessageLog(GrGLuint count, GrGLsizei bufSize, GrGLenum* sources, GrGLenum* types, GrGLuint* ids, GrGLenum* severities, GrGLsizei* lengths,  GrGLchar* messageLog) { return 0; }
+    virtual GrGLvoid pushDebugGroup(GrGLenum source, GrGLuint id, GrGLsizei length,  const GrGLchar * message) {}
+    virtual GrGLvoid popDebugGroup() {}
+    virtual GrGLvoid objectLabel(GrGLenum identifier, GrGLuint name, GrGLsizei length, const GrGLchar *label) {}
+
+protected:
+    // This must be called by leaf class
+    void init(GrGLStandard standard) {
+        fStandard = standard;
+        fExtensions.init(standard, fFunctions.fGetString, fFunctions.fGetStringi,
+                         fFunctions.fGetIntegerv, nullptr, GR_EGL_NO_DISPLAY);
+    }
+    GrGLTestInterface();
+};
+
+#endif
diff --git a/src/gpu/gl/SkNullGLContext.cpp b/src/gpu/gl/SkNullGLContext.cpp
index c6e01c341c..95b0e5ef47 100644
--- a/src/gpu/gl/SkNullGLContext.cpp
+++ b/src/gpu/gl/SkNullGLContext.cpp
@@ -8,578 +8,6 @@
 
 #include "gl/SkNullGLContext.h"
 #include "gl/GrGLInterface.h"
-#include "GrGLDefines.h"
-#include "GrGLNoOpInterface.h"
-#include "SkTDArray.h"
-#include "SkTLS.h"
-
-static SkNullGLContext::ContextState* current_context();
-
-/////////////////////////////////////////////////////////////////////////////////////////////////
-
-class BufferObj {
-public:
-    
-
-    BufferObj(GrGLuint id) : fID(id), fDataPtr(nullptr), fSize(0), fMapped(false) {}
-    ~BufferObj() { delete[] fDataPtr; }
-
-    void allocate(GrGLsizeiptr size, const GrGLchar* dataPtr) {
-        if (fDataPtr) {
-            SkASSERT(0 != fSize);
-            delete[] fDataPtr;
-        }
-
-        fSize = size;
-        fDataPtr = new char[size];
-    }
-
-    GrGLuint id() const          { return fID; }
-    GrGLchar* dataPtr()          { return fDataPtr; }
-    GrGLsizeiptr size() const    { return fSize; }
-
-    void setMapped(bool mapped)  { fMapped = mapped; }
-    bool mapped() const          { return fMapped; }
-
-private:
-    GrGLuint     fID;
-    GrGLchar*    fDataPtr;
-    GrGLsizeiptr fSize;         // size in bytes
-    bool         fMapped;
-};
-
-// This class maintains a sparsely populated array of buffer pointers.
-class BufferManager {
-public:
-    
-
-    BufferManager() : fFreeListHead(kFreeListEnd) {}
-
-    ~BufferManager() {
-        // nullptr out the entries that are really free list links rather than ptrs before deleting.
-        intptr_t curr = fFreeListHead;
-        while (kFreeListEnd != curr) {
-            intptr_t next = reinterpret_cast<intptr_t>(fBuffers[SkToS32(curr)]);
-            fBuffers[SkToS32(curr)] = nullptr;
-            curr = next;
-        }
-
-        fBuffers.deleteAll();
-    }
-
-    BufferObj* lookUp(GrGLuint id) {
-        BufferObj* buffer = fBuffers[id];
-        SkASSERT(buffer && buffer->id() == id);
-        return buffer;
-    }
-
-    BufferObj* create() {
-        GrGLuint id;
-        BufferObj* buffer;
-
-        if (kFreeListEnd == fFreeListHead) {
-            // no free slots - create a new one
-            id = fBuffers.count();
-            buffer = new BufferObj(id);
-            *fBuffers.append() = buffer;
-        } else {
-            // grab the head of the free list and advance the head to the next free slot.
-            id = static_cast<GrGLuint>(fFreeListHead);
-            fFreeListHead = reinterpret_cast<intptr_t>(fBuffers[id]);
-
-            buffer = new BufferObj(id);
-            fBuffers[id] = buffer;
-        }
-
-        return buffer;
-    }
-
-    void free(BufferObj* buffer) {
-        SkASSERT(fBuffers.count() > 0);
-
-        GrGLuint id = buffer->id();
-        delete buffer;
-
-        fBuffers[id] = reinterpret_cast<BufferObj*>(fFreeListHead);
-        fFreeListHead = id;
-    }
-
-private:
-    static const intptr_t kFreeListEnd = -1;
-    // Index of the first entry of fBuffers in the free list. Free slots in fBuffers are indices to
-    // the next free slot. The last free slot has a value of kFreeListEnd.
-    intptr_t                fFreeListHead;
-    SkTDArray<BufferObj*>   fBuffers;
-};
-
-/**
- * The state object for the null interface.
- */
-class SkNullGLContext::ContextState : public SkRefCnt {
-public:
-    
-
-    BufferManager   fBufferManager;
-    GrGLuint        fCurrArrayBuffer;
-    GrGLuint        fCurrElementArrayBuffer;
-    GrGLuint        fCurrPixelPackBuffer;
-    GrGLuint        fCurrPixelUnpackBuffer;
-    GrGLuint        fCurrProgramID;
-    GrGLuint        fCurrShaderID;
-
-
-    ContextState()
-        : fCurrArrayBuffer(0)
-        , fCurrElementArrayBuffer(0)
-        , fCurrPixelPackBuffer(0)
-        , fCurrPixelUnpackBuffer(0)
-        , fCurrProgramID(0)
-        , fCurrShaderID(0) {}
-
-    static ContextState* Get() { return current_context(); }
-};
-
-typedef SkNullGLContext::ContextState State;
-
-// Functions not declared in GrGLBogusInterface.h (not common with the Debug GL interface).
-
-namespace { // added to suppress 'no previous prototype' warning
-
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLActiveTexture(GrGLenum texture) {}
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLAttachShader(GrGLuint program, GrGLuint shader) {}
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLBeginQuery(GrGLenum target, GrGLuint id) {}
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLBindAttribLocation(GrGLuint program, GrGLuint index, const char* name) {}
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLBindTexture(GrGLenum target, GrGLuint texture) {}
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLBindVertexArray(GrGLuint id) {}
-
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLGenBuffers(GrGLsizei n, GrGLuint* ids) {
-    State* state = State::Get();
-    for (int i = 0; i < n; ++i) {
-        BufferObj* buffer = state->fBufferManager.create();
-        ids[i] = buffer->id();
-    }
-}
-
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLGenerateMipmap(GrGLenum target) {}
-
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLBufferData(GrGLenum target,
-                                              GrGLsizeiptr size,
-                                              const GrGLvoid* data,
-                                              GrGLenum usage) {
-    State* state = State::Get();
-    GrGLuint id = 0;
-
-    switch (target) {
-    case GR_GL_ARRAY_BUFFER:
-        id = state->fCurrArrayBuffer;
-        break;
-    case GR_GL_ELEMENT_ARRAY_BUFFER:
-        id = state->fCurrElementArrayBuffer;
-        break;
-    case GR_GL_PIXEL_PACK_BUFFER:
-        id = state->fCurrPixelPackBuffer;
-        break;
-    case GR_GL_PIXEL_UNPACK_BUFFER:
-        id = state->fCurrPixelUnpackBuffer;
-        break;
-    default:
-        SkFAIL("Unexpected target to nullGLBufferData");
-        break;
-    }
-
-    if (id > 0) {
-        BufferObj* buffer = state->fBufferManager.lookUp(id);
-        buffer->allocate(size, (const GrGLchar*) data);
-    }
-}
-
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLPixelStorei(GrGLenum pname, GrGLint param) {}
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLReadPixels(GrGLint x, GrGLint y, GrGLsizei width, GrGLsizei height, GrGLenum format, GrGLenum type, GrGLvoid* pixels) {}
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLUseProgram(GrGLuint program) {}
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLViewport(GrGLint x, GrGLint y, GrGLsizei width, GrGLsizei height) {}
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLBindFramebuffer(GrGLenum target, GrGLuint framebuffer) {}
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLBindRenderbuffer(GrGLenum target, GrGLuint renderbuffer) {}
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLDeleteFramebuffers(GrGLsizei n, const GrGLuint *framebuffers) {}
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLDeleteRenderbuffers(GrGLsizei n, const GrGLuint *renderbuffers) {}
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLFramebufferRenderbuffer(GrGLenum target, GrGLenum attachment, GrGLenum renderbuffertarget, GrGLuint renderbuffer) {}
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLFramebufferTexture2D(GrGLenum target, GrGLenum attachment, GrGLenum textarget, GrGLuint texture, GrGLint level) {}
-
-GrGLuint GR_GL_FUNCTION_TYPE nullGLCreateProgram() {
-    return ++State::Get()->fCurrProgramID;
-}
-
-GrGLuint GR_GL_FUNCTION_TYPE nullGLCreateShader(GrGLenum type) {
-    return ++State::Get()->fCurrShaderID;
-}
-
-// same delete used for shaders and programs
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLDelete(GrGLuint program) {
-}
-
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLBindBuffer(GrGLenum target, GrGLuint buffer) {
-    State* state = State::Get();
-    switch (target) {
-    case GR_GL_ARRAY_BUFFER:
-        state->fCurrArrayBuffer = buffer;
-        break;
-    case GR_GL_ELEMENT_ARRAY_BUFFER:
-        state->fCurrElementArrayBuffer = buffer;
-        break;
-    case GR_GL_PIXEL_PACK_BUFFER:
-        state->fCurrPixelPackBuffer = buffer;
-        break;
-    case GR_GL_PIXEL_UNPACK_BUFFER:
-        state->fCurrPixelUnpackBuffer = buffer;
-        break;
-    }
-}
-
-// deleting a bound buffer has the side effect of binding 0
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLDeleteBuffers(GrGLsizei n, const GrGLuint* ids) {
-    State* state = State::Get();
-    for (int i = 0; i < n; ++i) {
-        if (ids[i] == state->fCurrArrayBuffer) {
-            state->fCurrArrayBuffer = 0;
-        }
-        if (ids[i] == state->fCurrElementArrayBuffer) {
-            state->fCurrElementArrayBuffer = 0;
-        }
-        if (ids[i] == state->fCurrPixelPackBuffer) {
-            state->fCurrPixelPackBuffer = 0;
-        }
-        if (ids[i] == state->fCurrPixelUnpackBuffer) {
-            state->fCurrPixelUnpackBuffer = 0;
-        }
-
-        BufferObj* buffer = state->fBufferManager.lookUp(ids[i]);
-        state->fBufferManager.free(buffer);
-    }
-}
-
-GrGLvoid* GR_GL_FUNCTION_TYPE nullGLMapBufferRange(GrGLenum target, GrGLintptr offset,
-                                                   GrGLsizeiptr length, GrGLbitfield access) {
-    State* state = State::Get();
-    GrGLuint id = 0;
-    switch (target) {
-        case GR_GL_ARRAY_BUFFER:
-            id = state->fCurrArrayBuffer;
-            break;
-        case GR_GL_ELEMENT_ARRAY_BUFFER:
-            id = state->fCurrElementArrayBuffer;
-            break;
-        case GR_GL_PIXEL_PACK_BUFFER:
-            id = state->fCurrPixelPackBuffer;
-            break;
-        case GR_GL_PIXEL_UNPACK_BUFFER:
-            id = state->fCurrPixelUnpackBuffer;
-            break;
-    }
-
-    if (id > 0) {
-        // We just ignore the offset and length here.
-        BufferObj* buffer = state->fBufferManager.lookUp(id);
-        SkASSERT(!buffer->mapped());
-        buffer->setMapped(true);
-        return buffer->dataPtr();
-    }
-    return nullptr;
-}
-
-GrGLvoid* GR_GL_FUNCTION_TYPE nullGLMapBuffer(GrGLenum target, GrGLenum access) {
-    State* state = State::Get();
-    GrGLuint id = 0;
-    switch (target) {
-        case GR_GL_ARRAY_BUFFER:
-            id = state->fCurrArrayBuffer;
-            break;
-        case GR_GL_ELEMENT_ARRAY_BUFFER:
-            id = state->fCurrElementArrayBuffer;
-            break;
-        case GR_GL_PIXEL_PACK_BUFFER:
-            id = state->fCurrPixelPackBuffer;
-            break;
-        case GR_GL_PIXEL_UNPACK_BUFFER:
-            id = state->fCurrPixelUnpackBuffer;
-            break;
-    }
-
-    if (id > 0) {
-        BufferObj* buffer = state->fBufferManager.lookUp(id);
-        SkASSERT(!buffer->mapped());
-        buffer->setMapped(true);
-        return buffer->dataPtr();
-    }
-
-    SkASSERT(false);
-    return nullptr;            // no buffer bound to target
-}
-
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLFlushMappedBufferRange(GrGLenum target,
-                                                          GrGLintptr offset,
-                                                          GrGLsizeiptr length) {}
-
-
-GrGLboolean GR_GL_FUNCTION_TYPE nullGLUnmapBuffer(GrGLenum target) {
-    State* state = State::Get();
-    GrGLuint id = 0;
-    switch (target) {
-    case GR_GL_ARRAY_BUFFER:
-        id = state->fCurrArrayBuffer;
-        break;
-    case GR_GL_ELEMENT_ARRAY_BUFFER:
-        id = state->fCurrElementArrayBuffer;
-        break;
-    case GR_GL_PIXEL_PACK_BUFFER:
-        id = state->fCurrPixelPackBuffer;
-        break;
-    case GR_GL_PIXEL_UNPACK_BUFFER:
-        id = state->fCurrPixelUnpackBuffer;
-        break;
-    }
-    if (id > 0) {
-        BufferObj* buffer = state->fBufferManager.lookUp(id);
-        SkASSERT(buffer->mapped());
-        buffer->setMapped(false);
-        return GR_GL_TRUE;
-    }
-
-    GrAlwaysAssert(false);
-    return GR_GL_FALSE; // GR_GL_INVALID_OPERATION;
-}
-
-GrGLvoid GR_GL_FUNCTION_TYPE nullGLGetBufferParameteriv(GrGLenum target, GrGLenum pname, GrGLint* params) {
-    State* state = State::Get();
-    switch (pname) {
-        case GR_GL_BUFFER_MAPPED: {
-            *params = GR_GL_FALSE;
-            GrGLuint id = 0;
-            switch (target) {
-                case GR_GL_ARRAY_BUFFER:
-                    id = state->fCurrArrayBuffer;
-                    break;
-                case GR_GL_ELEMENT_ARRAY_BUFFER:
-                    id = state->fCurrElementArrayBuffer;
-                    break;
-                case GR_GL_PIXEL_PACK_BUFFER:
-                    id = state->fCurrPixelPackBuffer;
-                    break;
-                case GR_GL_PIXEL_UNPACK_BUFFER:
-                    id = state->fCurrPixelUnpackBuffer;
-                    break;
-            }
-            if (id > 0) {
-                BufferObj* buffer = state->fBufferManager.lookUp(id);
-                if (buffer->mapped()) {
-                    *params = GR_GL_TRUE;
-                }
-            }
-            break; }
-        default:
-            SkFAIL("Unexpected pname to GetBufferParamateriv");
-            break;
-    }
-};
-
-class NullInterface : public GrGLInterface {
-public:
-    NullInterface(State* state) : fState(SkRef(state)) {}
-    ~NullInterface() override {
-        fState->unref();
-    }
-    State* fState;
-};
-
-} // end anonymous namespace
-
-static GrGLInterface* create_null_interface(State* state) {
-    GrGLInterface* interface = new NullInterface(state);
-
-    interface->fStandard = kGL_GrGLStandard;
-
-    GrGLInterface::Functions* functions = &interface->fFunctions;
-    functions->fActiveTexture = nullGLActiveTexture;
-    functions->fAttachShader = nullGLAttachShader;
-    functions->fBeginQuery = nullGLBeginQuery;
-    functions->fBindAttribLocation = nullGLBindAttribLocation;
-    functions->fBindBuffer = nullGLBindBuffer;
-    functions->fBindFragDataLocation = noOpGLBindFragDataLocation;
-    functions->fBindTexture = nullGLBindTexture;
-    functions->fBindVertexArray = nullGLBindVertexArray;
-    functions->fBlendColor = noOpGLBlendColor;
-    functions->fBlendEquation = noOpGLBlendEquation;
-    functions->fBlendFunc = noOpGLBlendFunc;
-    functions->fBufferData = nullGLBufferData;
-    functions->fBufferSubData = noOpGLBufferSubData;
-    functions->fClear = noOpGLClear;
-    functions->fClearColor = noOpGLClearColor;
-    functions->fClearStencil = noOpGLClearStencil;
-    functions->fColorMask = noOpGLColorMask;
-    functions->fCompileShader = noOpGLCompileShader;
-    functions->fCompressedTexImage2D = noOpGLCompressedTexImage2D;
-    functions->fCompressedTexSubImage2D = noOpGLCompressedTexSubImage2D;
-    functions->fCopyTexSubImage2D = noOpGLCopyTexSubImage2D;
-    functions->fCreateProgram = nullGLCreateProgram;
-    functions->fCreateShader = nullGLCreateShader;
-    functions->fCullFace = noOpGLCullFace;
-    functions->fDeleteBuffers = nullGLDeleteBuffers;
-    functions->fDeleteProgram = nullGLDelete;
-    functions->fDeleteQueries = noOpGLDeleteIds;
-    functions->fDeleteShader = nullGLDelete;
-    functions->fDeleteTextures = noOpGLDeleteIds;
-    functions->fDeleteVertexArrays = noOpGLDeleteIds;
-    functions->fDepthMask = noOpGLDepthMask;
-    functions->fDisable = noOpGLDisable;
-    functions->fDisableVertexAttribArray = noOpGLDisableVertexAttribArray;
-    functions->fDrawArrays = noOpGLDrawArrays;
-    functions->fDrawArraysInstanced = noOpGLDrawArraysInstanced;
-    functions->fDrawBuffer = noOpGLDrawBuffer;
-    functions->fDrawBuffers = noOpGLDrawBuffers;
-    functions->fDrawElements = noOpGLDrawElements;
-    functions->fDrawElementsInstanced = noOpGLDrawElementsInstanced;
-    functions->fEnable = noOpGLEnable;
-    functions->fEnableVertexAttribArray = noOpGLEnableVertexAttribArray;
-    functions->fEndQuery = noOpGLEndQuery;
-    functions->fFinish = noOpGLFinish;
-    functions->fFlush = noOpGLFlush;
-    functions->fFlushMappedBufferRange = nullGLFlushMappedBufferRange;
-    functions->fFrontFace = noOpGLFrontFace;
-    functions->fGenBuffers = nullGLGenBuffers;
-    functions->fGenerateMipmap = nullGLGenerateMipmap;
-    functions->fGenQueries = noOpGLGenIds;
-    functions->fGenTextures = noOpGLGenIds;
-    functions->fGenVertexArrays = noOpGLGenIds;
-    functions->fGetBufferParameteriv = nullGLGetBufferParameteriv;
-    functions->fGetError = noOpGLGetError;
-    functions->fGetIntegerv = noOpGLGetIntegerv;
-    functions->fGetMultisamplefv = noOpGLGetMultisamplefv;
-    functions->fGetQueryObjecti64v = noOpGLGetQueryObjecti64v;
-    functions->fGetQueryObjectiv = noOpGLGetQueryObjectiv;
-    functions->fGetQueryObjectui64v = noOpGLGetQueryObjectui64v;
-    functions->fGetQueryObjectuiv = noOpGLGetQueryObjectuiv;
-    functions->fGetQueryiv = noOpGLGetQueryiv;
-    functions->fGetProgramInfoLog = noOpGLGetInfoLog;
-    functions->fGetProgramiv = noOpGLGetShaderOrProgramiv;
-    functions->fGetShaderInfoLog = noOpGLGetInfoLog;
-    functions->fGetShaderiv = noOpGLGetShaderOrProgramiv;
-    functions->fGetString = noOpGLGetString;
-    functions->fGetStringi = noOpGLGetStringi;
-    functions->fGetTexLevelParameteriv = noOpGLGetTexLevelParameteriv;
-    functions->fGetUniformLocation = noOpGLGetUniformLocation;
-    functions->fInsertEventMarker = noOpGLInsertEventMarker;
-    functions->fLineWidth = noOpGLLineWidth;
-    functions->fLinkProgram = noOpGLLinkProgram;
-    functions->fMapBuffer = nullGLMapBuffer;
-    functions->fMapBufferRange = nullGLMapBufferRange;
-    functions->fPixelStorei = nullGLPixelStorei;
-    functions->fPopGroupMarker = noOpGLPopGroupMarker;
-    functions->fPushGroupMarker = noOpGLPushGroupMarker;
-    functions->fQueryCounter = noOpGLQueryCounter;
-    functions->fReadBuffer = noOpGLReadBuffer;
-    functions->fReadPixels = nullGLReadPixels;
-    functions->fScissor = noOpGLScissor;
-    functions->fShaderSource = noOpGLShaderSource;
-    functions->fStencilFunc = noOpGLStencilFunc;
-    functions->fStencilFuncSeparate = noOpGLStencilFuncSeparate;
-    functions->fStencilMask = noOpGLStencilMask;
-    functions->fStencilMaskSeparate = noOpGLStencilMaskSeparate;
-    functions->fStencilOp = noOpGLStencilOp;
-    functions->fStencilOpSeparate = noOpGLStencilOpSeparate;
-    functions->fTexBuffer = noOpGLTexBuffer;
-    functions->fTexImage2D = noOpGLTexImage2D;
-    functions->fTexParameteri = noOpGLTexParameteri;
-    functions->fTexParameteriv = noOpGLTexParameteriv;
-    functions->fTexSubImage2D = noOpGLTexSubImage2D;
-    functions->fTexStorage2D = noOpGLTexStorage2D;
-    functions->fDiscardFramebuffer = noOpGLDiscardFramebuffer;
-    functions->fUniform1f = noOpGLUniform1f;
-    functions->fUniform1i = noOpGLUniform1i;
-    functions->fUniform1fv = noOpGLUniform1fv;
-    functions->fUniform1iv = noOpGLUniform1iv;
-    functions->fUniform2f = noOpGLUniform2f;
-    functions->fUniform2i = noOpGLUniform2i;
-    functions->fUniform2fv = noOpGLUniform2fv;
-    functions->fUniform2iv = noOpGLUniform2iv;
-    functions->fUniform3f = noOpGLUniform3f;
-    functions->fUniform3i = noOpGLUniform3i;
-    functions->fUniform3fv = noOpGLUniform3fv;
-    functions->fUniform3iv = noOpGLUniform3iv;
-    functions->fUniform4f = noOpGLUniform4f;
-    functions->fUniform4i = noOpGLUniform4i;
-    functions->fUniform4fv = noOpGLUniform4fv;
-    functions->fUniform4iv = noOpGLUniform4iv;
-    functions->fUniformMatrix2fv = noOpGLUniformMatrix2fv;
-    functions->fUniformMatrix3fv = noOpGLUniformMatrix3fv;
-    functions->fUniformMatrix4fv = noOpGLUniformMatrix4fv;
-    functions->fUnmapBuffer = nullGLUnmapBuffer;
-    functions->fUseProgram = nullGLUseProgram;
-    functions->fVertexAttrib1f = noOpGLVertexAttrib1f;
-    functions->fVertexAttrib2fv = noOpGLVertexAttrib2fv;
-    functions->fVertexAttrib3fv = noOpGLVertexAttrib3fv;
-    functions->fVertexAttrib4fv = noOpGLVertexAttrib4fv;
-    functions->fVertexAttribDivisor = noOpGLVertexAttribDivisor;
-    functions->fVertexAttribIPointer = noOpGLVertexAttribIPointer;
-    functions->fVertexAttribPointer = noOpGLVertexAttribPointer;
-    functions->fViewport = nullGLViewport;
-    functions->fBindFramebuffer = nullGLBindFramebuffer;
-    functions->fBindRenderbuffer = nullGLBindRenderbuffer;
-    functions->fCheckFramebufferStatus = noOpGLCheckFramebufferStatus;
-    functions->fDeleteFramebuffers = nullGLDeleteFramebuffers;
-    functions->fDeleteRenderbuffers = nullGLDeleteRenderbuffers;
-    functions->fFramebufferRenderbuffer = nullGLFramebufferRenderbuffer;
-    functions->fFramebufferTexture2D = nullGLFramebufferTexture2D;
-    functions->fGenFramebuffers = noOpGLGenIds;
-    functions->fGenRenderbuffers = noOpGLGenIds;
-    functions->fGetFramebufferAttachmentParameteriv = noOpGLGetFramebufferAttachmentParameteriv;
-    functions->fGetRenderbufferParameteriv = noOpGLGetRenderbufferParameteriv;
-    functions->fRenderbufferStorage = noOpGLRenderbufferStorage;
-    functions->fRenderbufferStorageMultisample = noOpGLRenderbufferStorageMultisample;
-    functions->fBlitFramebuffer = noOpGLBlitFramebuffer;
-    functions->fResolveMultisampleFramebuffer = noOpGLResolveMultisampleFramebuffer;
-    functions->fMatrixLoadf = noOpGLMatrixLoadf;
-    functions->fMatrixLoadIdentity = noOpGLMatrixLoadIdentity;
-    functions->fBindFragDataLocationIndexed = noOpGLBindFragDataLocationIndexed;
-
-    interface->fExtensions.init(kGL_GrGLStandard, functions->fGetString, functions->fGetStringi,
-                                functions->fGetIntegerv, nullptr, GR_EGL_NO_DISPLAY);
-    return interface;
-}
-
-//////////////////////////////////////////////////////////////////////////////
-
-static void* create_tls() {
-    State** current = new State*;
-    *current = nullptr;
-    return current;
-}
-
-static void delete_tls(void* ctx) {
-    State** current = static_cast<State**>(ctx);
-    if (*current) {
-        (*current)->unref();
-    }
-    delete current;
-}
-
-static State* current_context() {
-    return *static_cast<State**>(SkTLS::Get(create_tls, delete_tls));
-}
-
-static void set_current_context(State* state) {
-    State** current = static_cast<State**>(SkTLS::Get(create_tls, delete_tls));
-    if (*current) {
-        (*current)->unref();
-    }
-    *current = state;
-    if (state) {
-        state->ref();
-    }
-}
-
-#if GR_GL_PER_GL_FUNC_CALLBACK
-static void set_current_context_from_interface(const GrGLInterface* interface) {
-    set_current_context(reinterpret_cast<State*>(interface->fCallbackData));
-}
-#endif
 
 SkNullGLContext* SkNullGLContext::Create() {
     SkNullGLContext* ctx = new SkNullGLContext;
@@ -591,18 +19,9 @@ SkNullGLContext* SkNullGLContext::Create() {
 }
 
 SkNullGLContext::SkNullGLContext() {
-    fState = new ContextState;
-    GrGLInterface* interface = create_null_interface(fState);
-    this->init(interface);
-#if GR_GL_PER_GL_FUNC_CALLBACK
-    interface->fCallback = set_current_context_from_interface;
-    interface->fCallbackData = reinterpret_cast<GrGLInterfaceCallbackData>(fState);
-#endif
+    this->init(GrGLCreateNullInterface());
 }
 
 SkNullGLContext::~SkNullGLContext() {
     this->teardown();
-    fState->unref();
 }
-
-void SkNullGLContext::onPlatformMakeCurrent() const { set_current_context(fState); }
diff --git a/src/gpu/gl/egl/SkCreatePlatformGLContext_egl.cpp b/src/gpu/gl/egl/SkCreatePlatformGLContext_egl.cpp
index 09b7323877..86e2ebc4cd 100644
--- a/src/gpu/gl/egl/SkCreatePlatformGLContext_egl.cpp
+++ b/src/gpu/gl/egl/SkCreatePlatformGLContext_egl.cpp
@@ -229,8 +229,10 @@ GrGLuint EGLGLContext::eglImageToExternalTexture(GrEGLImage image) const {
     if (!this->gl()->hasExtension("GL_OES_EGL_image_external")) {
         return 0;
     }
-    GrGLEGLImageTargetTexture2DProc glEGLImageTargetTexture2D = 
-            (GrGLEGLImageTargetTexture2DProc) eglGetProcAddress("glEGLImageTargetTexture2DOES");
+    typedef GrGLvoid (*EGLImageTargetTexture2DProc)(GrGLenum, GrGLeglImage);
+
+    EGLImageTargetTexture2DProc glEGLImageTargetTexture2D =
+        (EGLImageTargetTexture2DProc) eglGetProcAddress("glEGLImageTargetTexture2DOES");
     if (!glEGLImageTargetTexture2D) {
         return 0;
     }