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

src/gpu/gl/GrGLProgramDesc.cpp

Index: src/gpu/gl/GrGLProgramDesc.cpp
diff --git a/src/gpu/gl/GrGLProgramDesc.cpp b/src/gpu/gl/GrGLProgramDesc.cpp
index cff4a2bab6f46ab886fa4889d5c62e396b8239f8..ecd48e014810eb4158a452a256418bad0aaba159 100644
--- a/src/gpu/gl/GrGLProgramDesc.cpp
+++ b/src/gpu/gl/GrGLProgramDesc.cpp
@@ -89,6 +89,11 @@
     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));
 
@@ -143,7 +148,11 @@
 #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;
@@ -152,7 +161,9 @@
 
     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;