Replace GrExtractAlphaFragmentProcessor with DstIn compose processor

src/effects/gradients/SkLinearGradient.cpp

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "SkLinearGradient.h"
 
 static inline int repeat_bits(int x, const int bits) {
@@ skipping 421 matching lines @@
             *dstC++ = cache[toggle + index];
             toggle = next_dither_toggle16(toggle);
 
             dstX += SK_Scalar1;
         } while (--count != 0);
     }
 }
 
 #if SK_SUPPORT_GPU
 
-#include "effects/GrExtractAlphaFragmentProcessor.h"
 #include "gl/builders/GrGLProgramBuilder.h"
 #include "SkGr.h"
 
 /////////////////////////////////////////////////////////////////////
 
 class GrGLLinearGradient : public GrGLGradientEffect {
 public:
 
     GrGLLinearGradient(const GrProcessor&) {}
 
@@ skipping 102 matching lines @@
         SkMatrix inv;
         if (!localMatrix->invert(&inv)) {
             return nullptr;
         }
         matrix.postConcat(inv);
     }
     matrix.postConcat(fPtsToUnit);
 
     SkAutoTUnref<const GrFragmentProcessor> inner(
         GrLinearGradient::Create(context, procDataManager, *this, matrix, fTileMode));
-    return GrExtractAlphaFragmentProcessor::Create(inner);
+    return GrFragmentProcessor::MulOuputByInputAlpha(inner);
 }
 
 
 #endif
 
 #ifndef SK_IGNORE_TO_STRING
 void SkLinearGradient::toString(SkString* str) const {
     str->append("SkLinearGradient (");
 
     str->appendf("start: (%f, %f)", fStart.fX, fStart.fY);
     str->appendf(" end: (%f, %f) ", fEnd.fX, fEnd.fY);
 
     this->INHERITED::toString(str);
 
     str->append(")");
 }
 #endif