Use noperspective interpolation for 2D draws

src/gpu/glsl/GrGLSLFragmentShaderBuilder.cpp

 /*
  * Copyright 2014 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrGLSLFragmentShaderBuilder.h"
 #include "GrRenderTarget.h"
 #include "gl/GrGLGpu.h"
@@ skipping 158 matching lines @@
 const char* GrGLSLFragmentShaderBuilder::dstColor() {
     fHasReadDstColor = true;
 
     const char* override = fProgramBuilder->primitiveProcessor().getDestColorOverride();
     if (override != nullptr) {
         return override;
     }
 
     const GrGLSLCaps* glslCaps = fProgramBuilder->glslCaps();
     if (glslCaps->fbFetchSupport()) {
-        this->addFeature(1 << (GrGLSLFragmentShaderBuilder::kLastGLSLPrivateFeature + 1),
+        this->addFeature(1 << kFramebufferFetch_GLSLPrivateFeature,
                          glslCaps->fbFetchExtensionString());
 
         // Some versions of this extension string require declaring custom color output on ES 3.0+
         const char* fbFetchColorName = glslCaps->fbFetchColorName();
         if (glslCaps->fbFetchNeedsCustomOutput()) {
             this->enableCustomOutput();
             fOutputs[fCustomColorOutputIndex].setTypeModifier(GrShaderVar::kInOut_TypeModifier);
             fbFetchColorName = DeclaredColorOutputName();
         }
         return fbFetchColorName;
@@ skipping 82 matching lines @@
 }
 
 void GrGLSLFragmentBuilder::onAfterChildProcEmitCode() {
     SkASSERT(fSubstageIndices.count() >= 2);
     fSubstageIndices.pop_back();
     fSubstageIndices.back()++;
     int removeAt = fMangleString.findLastOf('_');
     fMangleString.remove(removeAt, fMangleString.size() - removeAt);
 }