Add support for GL_*_shader_framebuffer_fetch

src/gpu/gl/GrGLShaderBuilder.h

 /*
  * Copyright 2012 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrGLShaderBuilder_DEFINED
 #define GrGLShaderBuilder_DEFINED
 
@@ skipping 241 matching lines @@
       */
     const GrGLShaderVar& positionAttribute() const { return *fPositionVar; }
 
     /** Returns a vertex attribute that represents the local coords in the VS. This may be the same
         as positionAttribute() or it may not be. It depends upon whether the rendering code
         specified explicit local coords or not in the GrDrawState. */
     const GrGLShaderVar& localCoordsAttribute() const { return *fLocalCoordsVar; }
 
     /** Returns the color of the destination pixel. This may be NULL if no effect advertised
         that it will read the destination. */
-    const char* dstColor() const;
+    const char* dstColor();
 
     /**
      * Are explicit local coordinates provided as input to the vertex shader.
      */
     bool hasExplicitLocalCoords() const { return (fLocalCoordsVar != fPositionVar); }
 
     /**
      * Interfaces used by GrGLProgram.
      * TODO: Hide these from the GrEffects using friend or splitting this into two related classes.
      * Also, GrGLProgram's shader string construction should be moved to this class.
@@ skipping 66 matching lines @@
 
 private:
     enum {
         kNonStageIdx = -1,
     };
 
     /**
      * Features that should only be enabled by GrGLShaderBuilder itself.
      */
     enum GLSLPrivateFeature {
-        kFragCoordConventions_GLSLPrivateFeature = kLastGLSLFeature + 1
+        kFragCoordConventions_GLSLPrivateFeature = kLastGLSLFeature + 1,
+        kEXTShaderFramebufferFetch_GLSLPrivateFeature,
+        kNVShaderFramebufferFetch_GLSLPrivateFeature,
     };
     bool enablePrivateFeature(GLSLPrivateFeature);
 
     // If we ever have VS/GS features we can expand this to take a bitmask of ShaderType and track
     // the enables separately for each shader.
     void addFSFeature(uint32_t featureBit, const char* extensionName);
 
     // Interpretation of DstReadKey when generating code
     enum {
         kNoDstRead_DstReadKey         = 0,
@@ skipping 23 matching lines @@
     GrGLUniformManager::UniformHandle   fDstCopyScaleUniform;
 
     SkSTArray<10, AttributePair, true>  fEffectAttributes;
 
     GrGLShaderVar*                      fPositionVar;
     GrGLShaderVar*                      fLocalCoordsVar;
 
 };
 
 #endif