Revert of Makes GrGLProgramDesc's key store the lengths as well as offsets of the effect keys. (https://codereview.chromium.org/379113004/)

Reason for revert:
Most likely candidate for Valgrind failures:

[21:10:08.755668] ==3036== Use of uninitialised value of size 8
[21:10:08.755753] ==3036==    at 0x734AB2: GrGpuGL::ProgramCache::getProgram(GrGLProgramDesc const&, GrEffectStage const**, GrEffectStage const**) (GrGpuGL_program.cpp:107)
[21:10:08.755788] ==3036==    by 0x734ED2: GrGpuGL::flushGraphicsState(GrGpu::DrawType, GrDeviceCoordTexture const*) (GrGpuGL_program.cpp:253)
[21:10:08.755811] ==3036==    by 0x6E81C2: GrGpu::setupClipAndFlushState(GrGpu::DrawType, GrDeviceCoordTexture const*, GrDrawState::AutoRestoreEffects*, SkRect const*) (GrGpu.cpp:350)
[21:10:08.755837] ==3036==    by 0x6E9BE8: GrGpu::onDraw(GrDrawTarget::DrawInfo const&) (GrGpu.cpp:390)
[21:10:08.755858] ==3036==    by 0x6EEECE: GrInOrderDrawBuffer::flush() (GrDrawTarget.h:506)
[21:10:08.755879] ==3036==    by 0x6D0EB4: GrContext::flush(int) (GrContext.cpp:1327)
[21:10:08.755900] ==3036==    by 0x6D3F8F: GrContext::writeTexturePixels(GrTexture*, int, int, int, int, GrPixelConfig, void const*, unsigned long, unsigned int) (GrContext.cpp:1349)
[21:10:08.755922] ==3036==    by 0x6D39D7: GrContext::writeRenderTargetPixels(GrRenderTarget*, int, int, int, int, GrPixelConfig, void const*, unsigned long, unsigned int) (GrContext.cpp:1632)
[21:10:08.755949] ==3036==    by 0x6FFDF3: GrRenderTarget::writePixels(int, int, int, int, GrPixelConfig, void const*, unsigned long, unsigned int) (GrRenderTarget.cpp:45)
[21:10:08.755978] ==3036==    by 0x735563: SkGpuDevice::onWritePixels(SkImageInfo const&, void const*, unsigned long, int, int) (SkGpuDevice.cpp:280)
[21:10:08.756003] ==3036==    by 0x57A048: SkBaseDevice::writePixels(SkImageInfo const&, void const*, unsigned long, int, int) (SkDevice.cpp:106)
[21:10:08.756025] ==3036==    by 0x56D0AE: SkCanvas::writePixels(SkImageInfo const&, void const*, unsigned long, int, int) (SkCanvas.cpp:700)
[21:10:08.756050] ==3036==    by 0x56D156: SkCanvas::writePixels(SkBitmap const&, int, int) (SkCanvas.cpp:652)
[21:10:08.756077] ==3036==    by 0x5109B6: test_WritePixels(skiatest::Reporter*, GrContextFactory*) (WritePixelsTest.cpp:464)
[21:10:08.756099] ==3036==    by 0x51114C: skiatest::WritePixelsClass::onRun(skiatest::Reporter*) (WritePixelsTest.cpp:361)
[21:10:08.756122] ==3036==    by 0x406BE8: skiatest::Test::run() (Test.cpp:107)
[21:10:08.756145] ==3036==    by 0x4064C2: SkTestRunnable::run() (skia_test.cpp:109)
[21:10:08.756167] ==3036==    by 0x405D1A: tool_main(int, char**) (skia_test.cpp:221)
[21:10:08.756189] ==3036==    by 0x405F75: main (skia_test.cpp:239)
[21:10:08.756211] ==3036==  Uninitialised value was created by a stack allocation
[21:10:08.756233] ==3036==    at 0x734CC8: GrGpuGL::flushGraphicsState(GrGpu::DrawType, GrDeviceCoordTexture const*) (GrGpuGL_program.cpp:213)

Original issue's description:
> Makes GrGLProgramDesc's key store the lengths as well as offsets of the effect keys.
>
> Makes it possible to use GrBackendEffectFactories other than GrTBEF by moving meta-key generation out of GrTBEF.
>
> Cleans up docs around GrBackendEffectFactory.
>
> Committed: https://skia.googlesource.com/skia/+/c0ea398aff8254e31152cbb94c9ab6150428e252

R=robertphillips@google.com, jvanverth@google.com, bsalomon@google.com
TBR=bsalomon@google.com, jvanverth@google.com, robertphillips@google.com
NOTREECHECKS=true
NOTRY=true

Author: mtklein@google.com

Review URL: https://codereview.chromium.org/394213002

7 files changed, 124 insertions, 213 deletions

diff --git a/include/gpu/GrBackendEffectFactory.h b/include/gpu/GrBackendEffectFactory.h
index ef9e436401..32f14f2746 100644
--- a/include/gpu/GrBackendEffectFactory.h
+++ b/include/gpu/GrBackendEffectFactory.h
@@ -14,12 +14,22 @@
 #include "SkTypes.h"
 #include "SkTArray.h"
 
+/** Given a GrEffect of a particular type, creates the corresponding graphics-backend-specific
+    effect object. Also tracks equivalence of shaders generated via a key. Each factory instance
+    is assigned a generation ID at construction. The ID of the return of GrEffect::getFactory()
+    is used as a type identifier. Thus a GrEffect subclass must return a singleton from
+    getFactory(). GrEffect subclasses should use the derived class GrTBackendEffectFactory that is
+    templated on the GrEffect subclass as their factory object. It requires that the GrEffect
+    subclass has a nested class (or typedef) GLEffect which is its GL implementation and a subclass
+    of GrGLEffect.
+ */
+
 class GrGLEffect;
 class GrGLCaps;
 class GrDrawEffect;
 
 /**
- * Used by effects to build their keys. It incorporates each per-effect key into a larger shader key.
+ * Used by effects to build their keys. It incorpates each per-effect key into a larger shader key.
  */
 class GrEffectKeyBuilder {
 public:
@@ -32,14 +42,6 @@ public:
         fData->push_back_n(4, reinterpret_cast<uint8_t*>(&v));
     }
 
-    /** Inserts count uint32_ts into the key. The returned pointer is only valid until the next
-        add*() call. */
-    uint32_t* SK_WARN_UNUSED_RESULT add32n(int count) {
-        SkASSERT(count > 0);
-        fCount += count;
-        return reinterpret_cast<uint32_t*>(fData->push_back_n(4 * count));
-    }
-
     size_t size() const { return sizeof(uint32_t) * fCount; }
 
 private:
@@ -47,74 +49,43 @@ private:
     int fCount;                     // number of uint32_ts added to fData by the effect.
 };
 
-/**
- * Given a GrEffect of a particular type, creates the corresponding graphics-backend-specific
- * effect object. It also tracks equivalence of shaders generated via a key. The factory for an
- * effect is accessed via GrEffect::getFactory(). Each factory instance is assigned an ID at
- * construction. The ID of GrEffect::getFactory() is used as a type identifier. Thus, a GrEffect
- * subclass must always return the same object from getFactory() and that factory object must be
- * unique to the GrEffect subclass (and unique from any further derived subclasses).
- *
- * Rather than subclassing this class themselves, it is recommended that GrEffect authors use 
- * the templated subclass GrTBackendEffectFactory by writing their getFactory() method as:
- *
- * const GrBackendEffectFactory& MyEffect::getFactory() const {
- *     return GrTBackendEffectFactory<MyEffect>::getInstance();
- * }
- *
- * Using GrTBackendEffectFactory places a few constraints on the effect. See that class's comments.
- */
 class GrBackendEffectFactory : SkNoncopyable {
 public:
     typedef uint32_t EffectKey;
 
-    /** 
-     * Generates an effect's key. The key is based on the aspects of the GrEffect object's
-     * configuration that affect GLSL code generation. Two GrEffect instances that would cause
-     * this->createGLInstance()->emitCode() to produce different code must produce different keys.
-     */
-    virtual void getGLEffectKey(const GrDrawEffect&, const GrGLCaps&, GrEffectKeyBuilder*) const = 0;
-
-    /**
-     * Creates a GrGLEffect instance that is used both to generate code for the GrEffect in a GLSL
-     * program and to manage updating uniforms for the program when it is used.
-     */
+    virtual bool getGLEffectKey(const GrDrawEffect&, const GrGLCaps&, GrEffectKeyBuilder*) const = 0;
     virtual GrGLEffect* createGLInstance(const GrDrawEffect&) const = 0;
 
-    /**
-     * Produces a human-reable name for the effect.
-     */
-    virtual const char* name() const = 0;
+    bool operator ==(const GrBackendEffectFactory& b) const {
+        return fEffectClassID == b.fEffectClassID;
+    }
+    bool operator !=(const GrBackendEffectFactory& b) const {
+        return !(*this == b);
+    }
 
-    /**
-     * A unique value for every instance of this factory. It is automatically incorporated into the
-     * effect's key. This allows keys generated by getGLEffectKey() to only be unique within a
-     * GrEffect subclass and not necessarily across subclasses.
-     */
-    uint32_t effectClassID() const { return fEffectClassID; }
+    virtual const char* name() const = 0;
 
 protected:
-    GrBackendEffectFactory() : fEffectClassID(GenID()) {}
-    virtual ~GrBackendEffectFactory() {}
-
-private:
     enum {
         kIllegalEffectClassID = 0,
     };
 
-    static uint32_t GenID() {
+    GrBackendEffectFactory() {
+        fEffectClassID = kIllegalEffectClassID;
+    }
+    virtual ~GrBackendEffectFactory() {}
+
+    static int32_t GenID() {
         // fCurrEffectClassID has been initialized to kIllegalEffectClassID. The
         // atomic inc returns the old value not the incremented value. So we add
         // 1 to the returned value.
-        uint32_t id = static_cast<uint32_t>(sk_atomic_inc(&fCurrEffectClassID)) + 1;
-        if (!id) {
-            SkFAIL("This should never wrap as it should only be called once for each GrEffect "
-                   "subclass.");
-        }
+        int32_t id = sk_atomic_inc(&fCurrEffectClassID) + 1;
         return id;
     }
 
-    const uint32_t fEffectClassID;
+    int32_t fEffectClassID;
+
+private:
     static int32_t fCurrEffectClassID;
 };
 
diff --git a/include/gpu/GrTBackendEffectFactory.h b/include/gpu/GrTBackendEffectFactory.h
index 251e8c7768..cd4c0a49e9 100644
--- a/include/gpu/GrTBackendEffectFactory.h
+++ b/include/gpu/GrTBackendEffectFactory.h
@@ -13,26 +13,7 @@
 #include "gl/GrGLProgramEffects.h"
 
 /**
- * Implements GrBackendEffectFactory for a GrEffect subclass as a singleton. This can be used by
- * most GrEffect subclasses to implement the GrEffect::getFactory() method:
- *
- * const GrBackendEffectFactory& MyEffect::getFactory() const {
- *     return GrTBackendEffectFactory<MyEffect>::getInstance();
- * }
- *
- * Using this class requires that the GrEffect subclass always produces the same GrGLEffect
- * subclass. Additionally, It adds the following requirements to the GrEffect and GrGLEffect
- * subclasses:
- *
- * 1. The GrGLEffect used by GrEffect subclass MyEffect must be named or typedef'ed to
- *    MyEffect::GLEffect.
- * 2. MyEffect::GLEffect must have a static function:
- *      EffectKey GenKey(const GrDrawEffect, const GrGLCaps&)
- *    which generates a key that maps 1 to 1 with code variations emitted by
- *    MyEffect::GLEffect::emitCode().
- * 3. MyEffect must have a static function:
- *      const char* Name()
- *    which returns a human-readable name for the effect.
+ * Implements GrBackendEffectFactory for a GrEffect subclass as a singleton.
  */
 template <typename EffectClass>
 class GrTBackendEffectFactory : public GrBackendEffectFactory {
@@ -40,17 +21,35 @@ class GrTBackendEffectFactory : public GrBackendEffectFactory {
 public:
     typedef typename EffectClass::GLEffect GLEffect;
 
-    /** Returns a human-readable name for the effect. Implemented using GLEffect::Name as described
-     *  in this class's comment. */
+    /** Returns a human-readable name that is accessible via GrEffect or
+        GrGLEffect and is consistent between the two of them.
+     */
     virtual const char* name() const SK_OVERRIDE { return EffectClass::Name(); }
 
-
-    /** Implemented using GLEffect::GenKey as described in this class's comment. */
-    virtual void getGLEffectKey(const GrDrawEffect& drawEffect,
+    /** Generates an effect's key. This enables caching of generated shaders. Part of the
+        id identifies the GrEffect subclass. The remainder is based on the aspects of the
+        GrEffect object's configuration that affect GLSL code generation. If this fails
+        then program generation should be aborted. Failure occurs if the effect uses more
+        transforms, attributes, or textures than the key has space for. */
+    virtual bool getGLEffectKey(const GrDrawEffect& drawEffect,
                                 const GrGLCaps& caps,
                                 GrEffectKeyBuilder* b) const SK_OVERRIDE {
+        SkASSERT(kIllegalEffectClassID != fEffectClassID);
         EffectKey effectKey = GLEffect::GenKey(drawEffect, caps);
+        EffectKey textureKey = GrGLProgramEffects::GenTextureKey(drawEffect, caps);
+        EffectKey transformKey = GrGLProgramEffects::GenTransformKey(drawEffect);
+        EffectKey attribKey = GrGLProgramEffects::GenAttribKey(drawEffect);
+        static const uint32_t kMetaKeyInvalidMask = ~((uint32_t) SK_MaxU16);
+        if ((textureKey | transformKey | attribKey | fEffectClassID) & kMetaKeyInvalidMask) {
+            return false;
+        }
+
+        // effectKey must be first because it is what will be returned by
+        // GrGLProgramDesc::EffectKeyProvider and passed to the GrGLEffect as its key. 
         b->add32(effectKey);
+        b->add32(textureKey << 16 | transformKey);
+        b->add32(fEffectClassID << 16 | attribKey);
+        return true;
     }
 
     /** Returns a new instance of the appropriate *GL* implementation class
@@ -60,7 +59,8 @@ public:
         return SkNEW_ARGS(GLEffect, (*this, drawEffect));
     }
 
-    /** This class is a singleton. This function returns the single instance. */
+    /** This class is a singleton. This function returns the single instance.
+     */
     static const GrBackendEffectFactory& getInstance() {
         static SkAlignedSTStorage<1, GrTBackendEffectFactory> gInstanceMem;
         static const GrTBackendEffectFactory* gInstance;
@@ -72,7 +72,9 @@ public:
     }
 
 protected:
-    GrTBackendEffectFactory() {}
+    GrTBackendEffectFactory() {
+        fEffectClassID = GenID();
+    }
 };
 
 #endif
diff --git a/src/gpu/gl/GrGLProgramDesc.cpp b/src/gpu/gl/GrGLProgramDesc.cpp
index 1807b84888..2c260cda52 100644
--- a/src/gpu/gl/GrGLProgramDesc.cpp
+++ b/src/gpu/gl/GrGLProgramDesc.cpp
@@ -14,14 +14,13 @@
 
 #include "SkChecksum.h"
 
-bool GrGLProgramDesc::GetEffectKeyAndUpdateStats(const GrEffectStage& stage,
-                                                 const GrGLCaps& caps,
-                                                 bool useExplicitLocalCoords,
-                                                 GrEffectKeyBuilder* b,
-                                                 uint16_t* effectKeySize,
-                                                 bool* setTrueIfReadsDst,
-                                                 bool* setTrueIfReadsPos,
-                                                 bool* setTrueIfHasVertexCode) {
+static inline bool get_key_and_update_stats(const GrEffectStage& stage,
+                                            const GrGLCaps& caps,
+                                            bool useExplicitLocalCoords,
+                                            GrEffectKeyBuilder* b, 
+                                            bool* setTrueIfReadsDst,
+                                            bool* setTrueIfReadsPos,
+                                            bool* setTrueIfHasVertexCode) {
     const GrBackendEffectFactory& factory = stage.getEffect()->getFactory();
     GrDrawEffect drawEffect(stage, useExplicitLocalCoords);
     if (stage.getEffect()->willReadDstColor()) {
@@ -33,17 +32,7 @@ bool GrGLProgramDesc::GetEffectKeyAndUpdateStats(const GrEffectStage& stage,
     if (stage.getEffect()->hasVertexCode()) {
         *setTrueIfHasVertexCode = true;
     }
-    factory.getGLEffectKey(drawEffect, caps, b);
-    size_t size = b->size();
-    if (size > SK_MaxU16) {
-        *effectKeySize = 0; // suppresses a warning.
-        return false;
-    }
-    *effectKeySize = SkToU16(size);
-    if (!GrGLProgramEffects::GenEffectMetaKey(drawEffect, caps, b)) {
-        return false;
-    }
-    return true;
+    return factory.getGLEffectKey(drawEffect, caps, b);
 }
 
 bool GrGLProgramDesc::Build(const GrDrawState& drawState,
@@ -116,54 +105,43 @@ bool GrGLProgramDesc::Build(const GrDrawState& drawState,
     if (!skipCoverage) {
         numStages += drawState.numCoverageStages() - firstEffectiveCoverageStage;
     }
-    GR_STATIC_ASSERT(0 == kEffectKeyOffsetsAndLengthOffset % sizeof(uint32_t));
+    GR_STATIC_ASSERT(0 == kEffectKeyLengthsOffset % sizeof(uint32_t));
     // Make room for everything up to and including the array of offsets to effect keys.
     desc->fKey.reset();
-    desc->fKey.push_back_n(kEffectKeyOffsetsAndLengthOffset + 2 * sizeof(uint32_t) * numStages);
+    desc->fKey.push_back_n(kEffectKeyLengthsOffset + sizeof(uint32_t) * numStages);
 
-    int offsetAndSizeIndex = 0;
+    size_t offset = desc->fKey.count();
+    int offsetIndex = 0;
 
     bool effectKeySuccess = true;
     if (!skipColor) {
         for (int s = firstEffectiveColorStage; s < drawState.numColorStages(); ++s) {
-            uint16_t* offsetAndSize =
-                reinterpret_cast<uint16_t*>(desc->fKey.begin() + kEffectKeyOffsetsAndLengthOffset +
-                                            offsetAndSizeIndex * 2 * sizeof(uint16_t));
+            uint32_t* offsetLocation = reinterpret_cast<uint32_t*>(desc->fKey.begin() +
+                                                                   kEffectKeyLengthsOffset +
+                                                                   offsetIndex * sizeof(uint32_t));
+            *offsetLocation = offset;
+            ++offsetIndex;
 
             GrEffectKeyBuilder b(&desc->fKey);
-            uint16_t effectKeySize;
-            uint32_t effectOffset = desc->fKey.count();
-            effectKeySuccess |= GetEffectKeyAndUpdateStats(
-                                    drawState.getColorStage(s), gpu->glCaps(),
-                                    requiresLocalCoordAttrib, &b,
-                                    &effectKeySize, &readsDst,
-                                    &readFragPosition, &hasVertexCode);
-            effectKeySuccess |= (effectOffset <= SK_MaxU16);
-
-            offsetAndSize[0] = SkToU16(effectOffset);
-            offsetAndSize[1] = effectKeySize;
-            ++offsetAndSizeIndex;
+            effectKeySuccess |= get_key_and_update_stats(drawState.getColorStage(s), gpu->glCaps(),
+                                                         requiresLocalCoordAttrib, &b, &readsDst,
+                                                         &readFragPosition, &hasVertexCode);
+            offset += b.size();
         }
     }
     if (!skipCoverage) {
         for (int s = firstEffectiveCoverageStage; s < drawState.numCoverageStages(); ++s) {
-            uint16_t* offsetAndSize =
-                reinterpret_cast<uint16_t*>(desc->fKey.begin() + kEffectKeyOffsetsAndLengthOffset +
-                                            offsetAndSizeIndex * 2 * sizeof(uint16_t));
-
+            uint32_t* offsetLocation = reinterpret_cast<uint32_t*>(desc->fKey.begin() +
+                                                                   kEffectKeyLengthsOffset +
+                                                                   offsetIndex * sizeof(uint32_t));
+            *offsetLocation = offset;
+            ++offsetIndex;
             GrEffectKeyBuilder b(&desc->fKey);
-            uint16_t effectKeySize;
-            uint32_t effectOffset = desc->fKey.count();
-            effectKeySuccess |= GetEffectKeyAndUpdateStats(
-                                    drawState.getCoverageStage(s), gpu->glCaps(),
-                                    requiresLocalCoordAttrib, &b,
-                                    &effectKeySize, &readsDst,
-                                    &readFragPosition, &hasVertexCode);
-            effectKeySuccess |= (effectOffset <= SK_MaxU16);
-
-            offsetAndSize[0] = SkToU16(effectOffset);
-            offsetAndSize[1] = effectKeySize;
-            ++offsetAndSizeIndex;
+            effectKeySuccess |= get_key_and_update_stats(drawState.getCoverageStage(s),
+                                                         gpu->glCaps(), requiresLocalCoordAttrib,
+                                                         &b, &readsDst, &readFragPosition,
+                                                         &hasVertexCode);
+            offset += b.size();
         }
     }
     if (!effectKeySuccess) {
diff --git a/src/gpu/gl/GrGLProgramDesc.h b/src/gpu/gl/GrGLProgramDesc.h
index c8aae19503..d7652f473c 100644
--- a/src/gpu/gl/GrGLProgramDesc.h
+++ b/src/gpu/gl/GrGLProgramDesc.h
@@ -172,20 +172,14 @@ private:
     // 1. uint32_t for total key length.
     // 2. uint32_t for a checksum.
     // 3. Header struct defined above.
-    // 4. An array of offsets to effect keys and their sizes (see 5). uint16_t for each
-    //    offset and size.
+    // 4. uint32_t offsets to beginning of every effects' key (see 5).
     // 5. per-effect keys. Each effect's key is a variable length array of uint32_t.
     enum {
-        // Part 1.
         kLengthOffset = 0,
-        // Part 2.
         kChecksumOffset = kLengthOffset + sizeof(uint32_t),
-        // Part 3.
         kHeaderOffset = kChecksumOffset + sizeof(uint32_t),
         kHeaderSize = SkAlign4(sizeof(KeyHeader)),
-        // Part 4.
-        // This is the offset in the overall key to the array of per-effect offset,length pairs.
-        kEffectKeyOffsetsAndLengthOffset = kHeaderOffset + kHeaderSize,
+        kEffectKeyLengthsOffset = kHeaderOffset + kHeaderSize,
     };
 
     template<typename T, size_t OFFSET> T* atOffset() {
@@ -200,16 +194,6 @@ private:
 
     KeyHeader* header() { return this->atOffset<KeyHeader, kHeaderOffset>(); }
 
-    // Shared code between setRandom() and Build().
-    static bool GetEffectKeyAndUpdateStats(const GrEffectStage& stage,
-                                           const GrGLCaps& caps,
-                                           bool useExplicitLocalCoords,
-                                           GrEffectKeyBuilder* b,
-                                           uint16_t* effectKeySize,
-                                           bool* setTrueIfReadsDst,
-                                           bool* setTrueIfReadsPos,
-                                           bool* setTrueIfHasVertexCode);
-
     void finalize();
 
     const KeyHeader& getHeader() const { return *this->atOffset<KeyHeader, kHeaderOffset>(); }
@@ -228,11 +212,9 @@ private:
         }
 
         EffectKey get(int index) const {
-            const uint16_t* offsets = reinterpret_cast<const uint16_t*>(
-                fDesc->fKey.begin() + kEffectKeyOffsetsAndLengthOffset);
-            // We store two uint16_ts per effect, one for the offset to the effect's key and one for
-            // its length. Here we just need the offset.
-            uint16_t offset = offsets[2 * (fBaseIndex + index)];
+            const uint32_t* offsets = reinterpret_cast<const uint32_t*>(fDesc->fKey.begin() +
+                                                                        kEffectKeyLengthsOffset);
+            uint32_t offset = offsets[fBaseIndex + index];
             return *reinterpret_cast<const EffectKey*>(fDesc->fKey.begin() + offset);
         }
     private:
@@ -243,7 +225,7 @@ private:
     enum {
         kMaxPreallocEffects = 8,
         kIntsPerEffect      = 4,    // This is an overestimate of the average effect key size.
-        kPreAllocSize = kEffectKeyOffsetsAndLengthOffset +
+        kPreAllocSize = kEffectKeyLengthsOffset +
                         kMaxPreallocEffects * sizeof(uint32_t) * kIntsPerEffect,
     };
 
diff --git a/src/gpu/gl/GrGLProgramEffects.cpp b/src/gpu/gl/GrGLProgramEffects.cpp
index 9936aa54ad..65d14fde11 100644
--- a/src/gpu/gl/GrGLProgramEffects.cpp
+++ b/src/gpu/gl/GrGLProgramEffects.cpp
@@ -114,27 +114,6 @@ SkMatrix get_transform_matrix(const GrDrawEffect& drawEffect, int transformIdx)
 
 ////////////////////////////////////////////////////////////////////////////////
 
-bool GrGLProgramEffects::GenEffectMetaKey(const GrDrawEffect& drawEffect, const GrGLCaps& caps,
-                                          GrEffectKeyBuilder* b) {
-
-    EffectKey textureKey = GrGLProgramEffects::GenTextureKey(drawEffect, caps);
-    EffectKey transformKey = GrGLProgramEffects::GenTransformKey(drawEffect);
-    EffectKey attribKey = GrGLProgramEffects::GenAttribKey(drawEffect);
-    uint32_t classID = drawEffect.effect()->getFactory().effectClassID();
-
-    // Currently we allow 16 bits for each of the above portions of the meta-key. Fail if they
-    // don't fit.
-    static const uint32_t kMetaKeyInvalidMask = ~((uint32_t) SK_MaxU16);
-    if ((textureKey | transformKey | attribKey | classID) & kMetaKeyInvalidMask) {
-        return false;
-    }
-
-    uint32_t* key = b->add32n(2);
-    key[0] = (textureKey << 16 | transformKey);
-    key[1] = (classID << 16 | attribKey);
-    return true;
-}
-
 EffectKey GrGLProgramEffects::GenAttribKey(const GrDrawEffect& drawEffect) {
     EffectKey key = 0;
     int numAttributes = drawEffect.getVertexAttribIndexCount();
diff --git a/src/gpu/gl/GrGLProgramEffects.h b/src/gpu/gl/GrGLProgramEffects.h
index c4d884392a..5a2fefd7d4 100644
--- a/src/gpu/gl/GrGLProgramEffects.h
+++ b/src/gpu/gl/GrGLProgramEffects.h
@@ -9,9 +9,9 @@
 #define GrGLProgramEffects_DEFINED
 
 #include "GrBackendEffectFactory.h"
-#include "GrGLUniformManager.h"
 #include "GrTexture.h"
 #include "GrTextureAccess.h"
+#include "GrGLUniformManager.h"
 
 class GrEffect;
 class GrEffectStage;
@@ -31,14 +31,11 @@ public:
     typedef GrGLUniformManager::UniformHandle UniformHandle;
 
     /**
-     * This class emits some of the code inserted into the shaders for an effect. The code it
-     * creates may be dependent on properties of the effect that the effect itself doesn't use
-     * in its key (e.g. the pixel format of textures used). So this class inserts a meta-key for
-     * every effect using this function. It is also responsible for inserting the effect's class ID
-     * which must be different for every GrEffect subclass. It can fail if an effect uses too many
-     * textures, attributes, etc for the space allotted in the meta-key.
+     * These methods generate different portions of an effect's final key.
      */
-    static bool GenEffectMetaKey(const GrDrawEffect&, const GrGLCaps&, GrEffectKeyBuilder*);
+    static EffectKey GenAttribKey(const GrDrawEffect&);
+    static EffectKey GenTransformKey(const GrDrawEffect&);
+    static EffectKey GenTextureKey(const GrDrawEffect&, const GrGLCaps&);
 
     virtual ~GrGLProgramEffects();
 
@@ -101,13 +98,6 @@ public:
     typedef SkTArray<TextureSampler> TextureSamplerArray;
 
 protected:
-    /**
-     * Helpers for GenEffectMetaKey.
-     */
-    static EffectKey GenAttribKey(const GrDrawEffect&);
-    static EffectKey GenTransformKey(const GrDrawEffect&);
-    static EffectKey GenTextureKey(const GrDrawEffect&, const GrGLCaps&);
-
     GrGLProgramEffects(int reserveCount)
         : fGLEffects(reserveCount)
         , fSamplers(reserveCount) {
diff --git a/tests/GLProgramsTest.cpp b/tests/GLProgramsTest.cpp
index 2264385902..dd0f80f42f 100644
--- a/tests/GLProgramsTest.cpp
+++ b/tests/GLProgramsTest.cpp
@@ -35,33 +35,42 @@ bool GrGLProgramDesc::setRandom(SkRandom* random,
     int numStages = numColorStages + numCoverageStages;
     fKey.reset();
 
-    GR_STATIC_ASSERT(0 == kEffectKeyOffsetsAndLengthOffset % sizeof(uint32_t));
+    GR_STATIC_ASSERT(0 == kEffectKeyLengthsOffset % sizeof(uint32_t));
 
     // Make room for everything up to and including the array of offsets to effect keys.
-    fKey.push_back_n(kEffectKeyOffsetsAndLengthOffset + 2 * sizeof(uint16_t) * numStages);
+    fKey.push_back_n(kEffectKeyLengthsOffset + sizeof(uint32_t) * numStages);
+
+    size_t offset = fKey.count();
+    int offsetIndex = 0;
 
     bool dstRead = false;
     bool fragPos = false;
     bool vertexCode = false;
     for (int s = 0; s < numStages; ++s) {
-        uint16_t* offsetAndSize = reinterpret_cast<uint16_t*>(fKey.begin() +
-                                                              kEffectKeyOffsetsAndLengthOffset +
-                                                              s * 2 * sizeof(uint16_t));
-        uint32_t effectKeyOffset = fKey.count();
-        if (effectKeyOffset > SK_MaxU16) {
-            fKey.reset();
-            return false;
-        }
+        uint32_t* offsetLocation = reinterpret_cast<uint32_t*>(fKey.begin() +
+                                                               kEffectKeyLengthsOffset +
+                                                               offsetIndex * sizeof(uint32_t));
+        *offsetLocation = offset;
+        ++offsetIndex;
+
+        const GrBackendEffectFactory& factory = stages[s]->getEffect()->getFactory();
         GrDrawEffect drawEffect(*stages[s], useLocalCoords);
         GrEffectKeyBuilder b(&fKey);
-        uint16_t effectKeySize;
-        if (!GetEffectKeyAndUpdateStats(*stages[s], gpu->glCaps(), useLocalCoords, &b,
-                                        &effectKeySize, &dstRead, &fragPos, &vertexCode)) {
+        if (!factory.getGLEffectKey(drawEffect, gpu->glCaps(), &b)) {
             fKey.reset();
             return false;
         }
-        offsetAndSize[0] = effectKeyOffset;
-        offsetAndSize[1] = effectKeySize;
+        if (stages[s]->getEffect()->willReadDstColor()) {
+            dstRead = true;
+        }
+        if (stages[s]->getEffect()->willReadFragmentPosition()) {
+            fragPos = true;
+        }
+        if (stages[s]->getEffect()->hasVertexCode()) {
+            vertexCode = true;
+        }
+
+        offset += b.size();
     }
 
     KeyHeader* header = this->header();