Force input coverage to be only a byte in gpu shaders.

src/gpu/GrPaint.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 "GrPaint.h"
 
@@ skipping 37 matching lines @@
 }
 
 bool GrPaint::getOpaqueAndKnownColor(GrColor* solidColor,
                                      uint32_t* solidColorKnownComponents) const {
 
     // TODO: Share this implementation with GrDrawState
 
     GrProcessor::InvariantOutput inout;
     inout.fColor = GrColorPackRGBA(fCoverage, fCoverage, fCoverage, fCoverage);
     inout.fValidFlags = kRGBA_GrColorComponentFlags;
-    inout.fIsSingleComponent = false;
+    inout.fIsSingleComponent = true;
     int count = fCoverageStages.count();
     for (int i = 0; i < count; ++i) {
         fCoverageStages[i].getProcessor()->computeInvariantOutput(&inout);
     }
     if (!inout.isSolidWhite()) {
         return false;
     }
 
     inout.fColor = fColor;
     inout.fValidFlags = kRGBA_GrColorComponentFlags;
@@ skipping 45 matching lines @@
                 case kIConstA_GrBlendCoeff:
                     *solidColorKnownComponents = 0;
                     break;
             }
         } else {
             solidColorKnownComponents = 0;
         }
     }
     return opaque;
 }