emitChild() takes an outputColor instead of generating one

src/gpu/gl/builders/GrGLFragmentShaderBuilder.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 "GrGLFragmentShaderBuilder.h"
 #include "GrGLProgramBuilder.h"
 #include "gl/GrGLGpu.h"
@@ skipping 284 matching lines @@
 
 void GrGLFragmentShaderBuilder::addVarying(GrGLVarying* v, GrSLPrecision fsPrec) {
     v->fFsIn = v->fVsOut;
     if (v->fGsOut) {
         v->fFsIn = v->fGsOut;
     }
     fInputs.push_back().set(v->fType, GrGLShaderVar::kVaryingIn_TypeModifier, v->fFsIn, fsPrec);
 }
 
 void GrGLFragmentBuilder::onBeforeChildProcEmitCode() {
-    fSubstageIndices.back()++;
+    SkASSERT(fSubstageIndices.count() >= 1);
     fSubstageIndices.push_back(0);
-    fMangleString.append(this->getMangleStringThisLevel());
+    // second-to-last value in the fSubstageIndices stack is the index of the child proc
+    // at that level which is currently emitting code.
+    fMangleString.appendf("_c%d", fSubstageIndices[fSubstageIndices.count() - 2]);
 }
 
 void GrGLFragmentBuilder::onAfterChildProcEmitCode() {
+    SkASSERT(fSubstageIndices.count() >= 2);
     fSubstageIndices.pop_back();
+    fSubstageIndices.back()++;
     int removeAt = fMangleString.findLastOf('_');
     fMangleString.remove(removeAt, fMangleString.size() - removeAt);
 }