Revert of Make the Sk GL context class an abstract base class (patchset #4 id:60001 of https://codereview.chromium.org/630843002/)

Reason for revert:
nanobech failing on Android

Original issue's description:
> Make the Sk GL context class an abstract base class
>
> Make the Sk GL context class, SkGLNativeContext, an abstract base class. Before,
> it depended on ifdefs to implement the platform dependent polymorphism.  Move
> the logic to subclasses of the various platform implementations.
>
> This a step to enable Skia embedders to compile dm and bench_pictures. The
> concrete goal is to support running these test apps with Chromium command buffer.
>
> With this change, Chromium can implement its own version of SkGLNativeContext
> that uses command buffer, and host the implementation in its own repository.
>
> Implements the above by renaming the SkGLContextHelper to SkGLContext and
> removing the unneeded SkGLNativeContext. Also removes
> SkGLNativeContext::AutoRestoreContext functionality, it appeared to be unused:
> no use in Skia code, and no tests.
>
> BUG=skia:2992
>
> Committed: https://skia.googlesource.com/skia/+/a90ed4e83897b45d6331ee4c54e1edd4054de9a8

TBR=kkinnunen@nvidia.com
NOTREECHECKS=true
NOTRY=true
BUG=skia:2992

Review URL: https://codereview.chromium.org/639793002

7 files changed, 154 insertions, 27 deletions

diff --git a/include/gpu/GrContextFactory.h b/include/gpu/GrContextFactory.h
index eff1f5834c..d78120ccb0 100644
--- a/include/gpu/GrContextFactory.h
+++ b/include/gpu/GrContextFactory.h
@@ -15,7 +15,7 @@
 #if SK_MESA
     #include "gl/SkMesaGLContext.h"
 #endif
-#include "gl/SkGLContext.h"
+#include "gl/SkNativeGLContext.h"
 #include "gl/SkNullGLContext.h"
 
 #include "GrContext.h"
@@ -130,12 +130,12 @@ public:
                 return fContexts[i].fGrContext;
             }
         }
-        SkAutoTUnref<SkGLContext> glCtx;
+        SkAutoTUnref<SkGLContextHelper> glCtx;
         SkAutoTUnref<GrContext> grCtx;
         switch (type) {
             case kNVPR_GLContextType: // fallthru
             case kNative_GLContextType:
-                glCtx.reset(SkCreatePlatformGLContext());
+                glCtx.reset(SkNEW(SkNativeGLContext));
                 break;
 #ifdef SK_ANGLE
             case kANGLE_GLContextType:
@@ -192,7 +192,7 @@ public:
 
     // Returns the GLContext of the given type. If it has not been created yet,
     // NULL is returned instead.
-    SkGLContext* getGLContext(GLContextType type) {
+    SkGLContextHelper* getGLContext(GLContextType type) {
         for (int i = 0; i < fContexts.count(); ++i) {
             if (fContexts[i].fType == type) {
                 return fContexts[i].fGLContext;
@@ -207,7 +207,7 @@ public:
 private:
     struct GPUContext {
         GLContextType             fType;
-        SkGLContext*              fGLContext;
+        SkGLContextHelper*        fGLContext;
         GrContext*                fGrContext;
     };
     SkTArray<GPUContext, true>    fContexts;
diff --git a/include/gpu/gl/SkANGLEGLContext.h b/include/gpu/gl/SkANGLEGLContext.h
index 18cdbdb213..c5f62ff3ce 100644
--- a/include/gpu/gl/SkANGLEGLContext.h
+++ b/include/gpu/gl/SkANGLEGLContext.h
@@ -10,12 +10,12 @@
 
 #if SK_ANGLE
 
-#include "SkGLContext.h"
+#include "SkGLContextHelper.h"
 
 #include <GLES2/gl2.h>
 #include <EGL/egl.h>
 
-class SkANGLEGLContext : public SkGLContext {
+class SkANGLEGLContext : public SkGLContextHelper {
 public:
     SkANGLEGLContext();
 
@@ -24,6 +24,17 @@ public:
     virtual void makeCurrent() const SK_OVERRIDE;
     virtual void swapBuffers() const SK_OVERRIDE;
 
+    class AutoContextRestore {
+    public:
+        AutoContextRestore();
+        ~AutoContextRestore();
+
+    private:
+        EGLContext fOldEGLContext;
+        EGLDisplay fOldDisplay;
+        EGLSurface fOldSurface;
+    };
+
 protected:
     virtual const GrGLInterface* createGLContext(
         GrGLStandard forcedGpuAPI) SK_OVERRIDE;
diff --git a/include/gpu/gl/SkDebugGLContext.h b/include/gpu/gl/SkDebugGLContext.h
index 792666332e..7db9579617 100644
--- a/include/gpu/gl/SkDebugGLContext.h
+++ b/include/gpu/gl/SkDebugGLContext.h
@@ -8,9 +8,9 @@
 #ifndef SkDebugGLContext_DEFINED
 #define SkDebugGLContext_DEFINED
 
-#include "SkGLContext.h"
+#include "SkGLContextHelper.h"
 
-class SkDebugGLContext : public SkGLContext {
+class SkDebugGLContext : public SkGLContextHelper {
 
 public:
     SkDebugGLContext() {}
diff --git a/include/gpu/gl/SkGLContext.h b/include/gpu/gl/SkGLContextHelper.h
index 83c9146c9b..c4d9bdf997 100644
--- a/include/gpu/gl/SkGLContext.h
+++ b/include/gpu/gl/SkGLContextHelper.h
@@ -5,8 +5,8 @@
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
-#ifndef SkGLContext_DEFINED
-#define SkGLContext_DEFINED
+#ifndef SkGLContextHelper_DEFINED
+#define SkGLContextHelper_DEFINED
 
 #include "GrGLInterface.h"
 
@@ -15,12 +15,12 @@
  * Provides a GrGLInterface struct of function pointers for the context.
  */
 
-class SK_API SkGLContext : public SkRefCnt {
+class SK_API SkGLContextHelper : public SkRefCnt {
 public:
-    SK_DECLARE_INST_COUNT(SkGLContext)
+    SK_DECLARE_INST_COUNT(SkGLContextHelper)
 
-    SkGLContext();
-    virtual ~SkGLContext();
+    SkGLContextHelper();
+    virtual ~SkGLContextHelper();
 
     /**
      * Initializes the context and makes it current.
@@ -81,14 +81,6 @@ private:
     typedef SkRefCnt INHERITED;
 };
 
-/** Creates platform-dependent GL context object
- * Note: If Skia embedder needs a custom GL context that sets up the GL
- * interface, this function should be implemented by the embedder.
- * Otherwise, the default implementation for the platform should be compiled in
- * the library.
- */
-SK_API SkGLContext* SkCreatePlatformGLContext();
-
 /**
  * Helper macros for using the GL context through the GrGLInterface. Example:
  * SK_GL(glCtx, GenTextures(1, &texID));
diff --git a/include/gpu/gl/SkMesaGLContext.h b/include/gpu/gl/SkMesaGLContext.h
index ef0017180c..28349ddd88 100644
--- a/include/gpu/gl/SkMesaGLContext.h
+++ b/include/gpu/gl/SkMesaGLContext.h
@@ -8,11 +8,11 @@
 #ifndef SkMesaGLContext_DEFINED
 #define SkMesaGLContext_DEFINED
 
-#include "SkGLContext.h"
+#include "SkGLContextHelper.h"
 
 #if SK_MESA
 
-class SkMesaGLContext : public SkGLContext {
+class SkMesaGLContext : public SkGLContextHelper {
 private:
     typedef intptr_t Context;
 
@@ -24,6 +24,19 @@ public:
     virtual void makeCurrent() const SK_OVERRIDE;
     virtual void swapBuffers() const SK_OVERRIDE;
 
+    class AutoContextRestore {
+    public:
+        AutoContextRestore();
+        ~AutoContextRestore();
+
+    private:
+        Context fOldContext;
+        GrGLint fOldWidth;
+        GrGLint fOldHeight;
+        GrGLint fOldFormat;
+        void*   fOldImage;
+    };
+
 protected:
     virtual const GrGLInterface* createGLContext(GrGLStandard forcedGpuAPI) SK_OVERRIDE;
     virtual void destroyGLContext() SK_OVERRIDE;
diff --git a/include/gpu/gl/SkNativeGLContext.h b/include/gpu/gl/SkNativeGLContext.h
new file mode 100644
index 0000000000..93b5b4183a
--- /dev/null
+++ b/include/gpu/gl/SkNativeGLContext.h
@@ -0,0 +1,111 @@
+
+/*
+ * Copyright 2011 Google Inc.
+ *
+ * Use of this source code is governed by a BSD-style license that can be
+ * found in the LICENSE file.
+ */
+#ifndef SkNativeGLContext_DEFINED
+#define SkNativeGLContext_DEFINED
+
+#include "SkGLContextHelper.h"
+
+/* This struct is taken from a mesa demo.  Please update as required */
+static const struct { int major, minor; } gl_versions[] = {
+   {1, 0},
+   {1, 1},
+   {1, 2},
+   {1, 3},
+   {1, 4},
+   {1, 5},
+   {2, 0},
+   {2, 1},
+   {3, 0},
+   {3, 1},
+   {3, 2},
+   {3, 3},
+   {4, 0},
+   {4, 1},
+   {4, 2},
+   {4, 3},
+   {4, 4},
+   {0, 0} /* end of list */
+};
+#define NUM_GL_VERSIONS SK_ARRAY_COUNT(gl_versions)
+
+#if defined(SK_BUILD_FOR_MAC)
+    #include <OpenGL/OpenGL.h>
+#elif SK_EGL
+    #include <GLES2/gl2.h>
+    #include <EGL/egl.h>
+#elif defined(SK_BUILD_FOR_UNIX)
+    #include <X11/Xlib.h>
+    #include <GL/glx.h>
+#elif defined(SK_BUILD_FOR_WIN32)
+    #include <windows.h>
+    #include <GL/GL.h>
+    #include "SkWGL.h"
+#endif
+
+class SkNativeGLContext : public SkGLContextHelper {
+public:
+    SkNativeGLContext();
+
+    virtual ~SkNativeGLContext();
+
+    virtual void makeCurrent() const SK_OVERRIDE;
+    virtual void swapBuffers() const SK_OVERRIDE;
+
+    class AutoContextRestore {
+    public:
+        AutoContextRestore();
+        ~AutoContextRestore();
+
+    private:
+    #if defined(SK_BUILD_FOR_MAC)
+        CGLContextObj fOldCGLContext;
+    #elif SK_EGL
+        EGLContext fOldEGLContext;
+        EGLDisplay fOldDisplay;
+        EGLSurface fOldSurface;
+    #elif defined(SK_BUILD_FOR_UNIX)
+        GLXContext fOldGLXContext;
+        Display* fOldDisplay;
+        GLXDrawable fOldDrawable;
+    #elif defined(SK_BUILD_FOR_WIN32)
+        HDC fOldHDC;
+        HGLRC fOldHGLRC;
+
+    #elif defined(SK_BUILD_FOR_IOS)
+        void* fEAGLContext;
+    #endif
+    };
+
+protected:
+    virtual const GrGLInterface* createGLContext(GrGLStandard forcedGpuAPI) SK_OVERRIDE;
+    virtual void destroyGLContext() SK_OVERRIDE;
+
+private:
+#if defined(SK_BUILD_FOR_MAC)
+    CGLContextObj fContext;
+#elif SK_EGL
+    EGLContext fContext;
+    EGLDisplay fDisplay;
+    EGLSurface fSurface;
+#elif defined(SK_BUILD_FOR_UNIX)
+    GLXContext fContext;
+    Display* fDisplay;
+    Pixmap fPixmap;
+    GLXPixmap fGlxPixmap;
+#elif defined(SK_BUILD_FOR_WIN32)
+    HWND fWindow;
+    HDC fDeviceContext;
+    HGLRC fGlRenderContext;
+    static ATOM gWC;
+    SkWGLPbufferContext* fPbufferContext;
+#elif defined(SK_BUILD_FOR_IOS)
+    void* fEAGLContext;
+#endif
+};
+
+#endif
diff --git a/include/gpu/gl/SkNullGLContext.h b/include/gpu/gl/SkNullGLContext.h
index 16621fc696..6c2a1d7e59 100644
--- a/include/gpu/gl/SkNullGLContext.h
+++ b/include/gpu/gl/SkNullGLContext.h
@@ -8,9 +8,9 @@
 #ifndef SkNullGLContext_DEFINED
 #define SkNullGLContext_DEFINED
 
-#include "SkGLContext.h"
+#include "SkGLContextHelper.h"
 
-class SK_API SkNullGLContext : public SkGLContext {
+class SK_API SkNullGLContext : public SkGLContextHelper {
 
 public:
     SkNullGLContext() {};