Implement color filter as GrGLEffect

src/gpu/gl/GrGLSL.h

 /*
  * Copyright 2011 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrGLSL_DEFINED
 #define GrGLSL_DEFINED
 
@@ skipping 179 matching lines @@
         } else if (kOnes_ExprType == fType) {
             return this->onesStr();
         }
         SkASSERT(!fExpr.isEmpty()); // Empty expressions should not be used.
         return fExpr.c_str();
     }
 
     static const char* zerosStr();
     static const char* onesStr();
 
+    bool isValid() const {
+        return kFullExpr_ExprType != fType || !fExpr.isEmpty();
+    }
+
 private:
     GrGLSLExpr(const char format[], const char in0[])
         : fType(kFullExpr_ExprType) {
         fExpr.appendf(format, in0);
     }
 
     GrGLSLExpr(const char format[], const char in0[], const char in1[])
         : fType(kFullExpr_ExprType) {
         fExpr.appendf(format, in0, in1);
     }
 
     GrGLSLExpr(const char format[], const char in0[], const char in1)
         : fType(kFullExpr_ExprType) {
         fExpr.appendf(format, in0, in1);
     }
 
     /** Given an expression of vecM, cast it to vecN. */
     template<int M>
     static GrGLSLExpr<N> VectorCast(const GrGLSLExpr<M>&);
 
-    bool isValid() const {
-        return kFullExpr_ExprType != fType || !fExpr.isEmpty();
-    }
-
     static const char* expandComponentStr();
     static const char* castStr();
 
 
     SkString fExpr;
     enum ExprType {
         kZeros_ExprType,
         kOnes_ExprType,
         kFullExpr_ExprType,
     };
@@ skipping 38 matching lines @@
 /**
  * Does an inplace mul, *=, of vec4VarName by mulFactor.
  * A semicolon and newline are added after the assignment.
  */
 void GrGLSLMulVarBy4f(SkString* outAppend, unsigned tabCnt,
                       const char* vec4VarName, const GrGLSLExpr<4>& mulFactor);
 
 #include "GrGLSL_impl.h"
 
 #endif