Implement color filter as GrGLEffect

src/gpu/gl/GrGLSL_impl.h

 /*
  * Copyright 2013 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrGLSL_impl_DEFINED
 #define GrGLSL_impl_DEFINED
 
@@ skipping 21 matching lines @@
 template<>
 inline const char* GrGLSLExpr<1>::zerosStr() {
     return "0";
 }
 
 template<>
 inline const char* GrGLSLExpr<1>::onesStr() {
     return "1";
 }
 
-// GrGLSLExpr<1>::expandComponentStr() is unimplemented because using it
-// is likely an error. This is now caught compile-time.
+// GrGLSLExpr<1>::expandComponentStr() is unimplemented because using it is
+// likely an error. This is now caught compile-time.
 
 template<>
 inline const char* GrGLSLExpr<1>::castStr() {
     return "(%s)";
 }
 
 template<>
 template<>
 inline GrGLSLExpr<4> GrGLSLExpr<4>::VectorCast(const GrGLSLExpr<4>& other) {
     return other;
@@ skipping 65 matching lines @@
 
 template<int N>
 GrGLSLExpr<N> GrGLSLExpr<N>::expandComponent(GrColorComponentFlags component) const {
     if (this->isZeros() || this->isOnes()) {
         return *this;
     }
     return GrGLSLExpr<N>(this->expandComponentStr(), this->c_str(), GrColorComponentFlagToChar(component));
 }
 
 #endif