Replace fWillReadFragmentPosition with a bitfield

src/gpu/glsl/GrGLSLProgramBuilder.h

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrGLSLProgramBuilder_DEFINED
 #define GrGLSLProgramBuilder_DEFINED
 
@@ skipping 87 matching lines @@
     void cleanupFragmentProcessors();
 
     void finalizeShaders();
 
 private:
     // reset is called by program creator between each processor's emit code.  It increments the
     // stage offset for variable name mangling, and also ensures verfication variables in the
     // fragment shader are cleared.
     void reset() {
         this->addStage();
-        fFS.reset();
+        SkDEBUGCODE(fFS.resetVerification();)
     }
     void addStage() { fStageIndex++; }
 
     class AutoStageAdvance {
     public:
         AutoStageAdvance(GrGLSLProgramBuilder* pb)
             : fPB(pb) {
             fPB->reset();
             // Each output to the fragment processor gets its own code section
             fPB->fFS.nextStage();
@@ skipping 15 matching lines @@
                                 int index,
                                 const GrGLSLExpr4& input,
                                 GrGLSLExpr4* output);
     void emitAndInstallXferProc(const GrXferProcessor&,
                                 const GrGLSLExpr4& colorIn,
                                 const GrGLSLExpr4& coverageIn,
                                 bool ignoresCoverage,
                                 GrPixelLocalStorageState plsState);
     void emitFSOutputSwizzle(bool hasSecondaryOutput);
 
+#ifdef SK_DEBUG
     void verify(const GrPrimitiveProcessor&);
     void verify(const GrXferProcessor&);
     void verify(const GrFragmentProcessor&);
+#endif
 
     virtual void emitSamplers(const GrProcessor& processor,
                               GrGLSLTextureSampler::TextureSamplerArray* outSamplers) = 0;
 
     GrGLSLPrimitiveProcessor::TransformsIn  fCoordTransforms;
     GrGLSLPrimitiveProcessor::TransformsOut fOutCoords;
 };
 
 #endif