Revert of Remove gpu shader optimatization for solid white or trans black colors

src/gpu/gl/GrGLProgramDesc.cpp

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrGLProgramDesc.h"
 #include "GrBackendEffectFactory.h"
 #include "GrDrawEffect.h"
@@ skipping 71 matching lines @@
     // descriptor will not affect program generation (because of the attribute
     // bindings in use or other descriptor field settings) it should be set
     // to a canonical value to avoid duplicate programs with different keys.
 
     bool requiresColorAttrib = !skipColor && drawState.hasColorVertexAttribute();
     bool requiresCoverageAttrib = !skipCoverage && drawState.hasCoverageVertexAttribute();
     // we only need the local coords if we're actually going to generate effect code
     bool requiresLocalCoordAttrib = !(skipCoverage  && skipColor) &&
                                     drawState.hasLocalCoordAttribute();
 
+    bool colorIsTransBlack = SkToBool(blendOpts & GrDrawState::kEmitTransBlack_BlendOptFlag);
+    bool colorIsSolidWhite = (blendOpts & GrDrawState::kEmitCoverage_BlendOptFlag) ||
+                             (!requiresColorAttrib && 0xffffffff == drawState.getColor()) ||
+                             (!inputColorIsUsed);
+
     int numEffects = (skipColor ? 0 : (drawState.numColorStages() - firstEffectiveColorStage)) +
                      (skipCoverage ? 0 : (drawState.numCoverageStages() - firstEffectiveCoverageStage));
 
     size_t newKeyLength = KeyLength(numEffects);
     bool allocChanged;
     desc->fKey.reset(newKeyLength, SkAutoMalloc::kAlloc_OnShrink, &allocChanged);
     if (allocChanged || !desc->fInitialized) {
         // make sure any padding in the header is zero if we we haven't used this allocation before.
         memset(desc->header(), 0, kHeaderSize);
     }
@@ skipping 34 matching lines @@
     // other than pass through values from the VS to the FS anyway).
 #if GR_GL_EXPERIMENTAL_GS
 #if 0
     header->fExperimentalGS = gpu->caps().geometryShaderSupport();
 #else
     header->fExperimentalGS = false;
 #endif
 #endif
     bool defaultToUniformInputs = GR_GL_NO_CONSTANT_ATTRIBUTES || gpu->caps()->pathRenderingSupport();
 
-    if (defaultToUniformInputs && !requiresColorAttrib) {
+    if (colorIsTransBlack) {
+        header->fColorInput = kTransBlack_ColorInput;
+    } else if (colorIsSolidWhite) {
+        header->fColorInput = kSolidWhite_ColorInput;
+    } else if (defaultToUniformInputs && !requiresColorAttrib) {
         header->fColorInput = kUniform_ColorInput;
     } else {
         header->fColorInput = kAttribute_ColorInput;
         header->fHasVertexCode = true;
     }
 
     bool covIsSolidWhite = !requiresCoverageAttrib && 0xffffffff == drawState.getCoverageColor();
 
-    if (covIsSolidWhite || !inputCoverageIsUsed) {
+    if (skipCoverage) {
+        header->fCoverageInput = kTransBlack_ColorInput;
+    } else if (covIsSolidWhite || !inputCoverageIsUsed) {
         header->fCoverageInput = kSolidWhite_ColorInput;
     } else if (defaultToUniformInputs && !requiresCoverageAttrib) {
         header->fCoverageInput = kUniform_ColorInput;
     } else {
         header->fCoverageInput = kAttribute_ColorInput;
         header->fHasVertexCode = true;
     }
 
     if (readsDst) {
         SkASSERT(NULL != dstCopy || gpu->caps()->dstReadInShaderSupport());
@@ skipping 99 matching lines @@
 
 GrGLProgramDesc& GrGLProgramDesc::operator= (const GrGLProgramDesc& other) {
     fInitialized = other.fInitialized;
     if (fInitialized) {
         size_t keyLength = other.keyLength();
         fKey.reset(keyLength);
         memcpy(fKey.get(), other.fKey.get(), keyLength);
     }
     return *this;
 }