emitChild() takes an outputColor instead of generating one

src/gpu/gl/GrGLFragmentProcessor.cpp

 /*
  * Copyright 2015 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #include "GrGLFragmentProcessor.h"
 #include "GrFragmentProcessor.h"
 #include "builders/GrGLFragmentShaderBuilder.h"
 #include "builders/GrGLProgramBuilder.h"
 
 void GrGLFragmentProcessor::setData(const GrGLProgramDataManager& pdman,
                                     const GrFragmentProcessor& processor) {
     this->onSetData(pdman, processor);
     SkASSERT(fChildProcessors.count() == processor.numChildProcessors());
     for (int i = 0; i < fChildProcessors.count(); ++i) {
         fChildProcessors[i]->setData(pdman, processor.childProcessor(i));
     }
 }
 
 void GrGLFragmentProcessor::emitChild(int childIndex, const char* inputColor,
-                                      SkString* outputColor, EmitArgs& args) {
+                                      const char* outputColor, EmitArgs& args) {
     GrGLFragmentBuilder* fb = args.fBuilder->getFragmentShaderBuilder();
     fb->onBeforeChildProcEmitCode();  // call first so mangleString is updated
 
     const GrFragmentProcessor& childProc = args.fFp.childProcessor(childIndex);
 
-    // Mangle the name of the outputColor
-    outputColor->set(args.fOutputColor);
-    outputColor->append(fb->getMangleStringThisLevel());
-
     /*
      * We now want to find the subset of coords and samplers that belong to the child and its
      * descendants and put that into childCoords and childSamplers. To do so, we'll do a forwards
      * linear search.
      *
      * Explanation:
      * Each GrFragmentProcessor has a copy of all the transforms and textures of itself and
      * all procs in its subtree. For example, suppose we have frag proc A, who has two children B
      * and D. B has a child C, and D has two children E and F. Each frag proc's transforms array
      * contains its own transforms, followed by the transforms of all its descendants (i.e. preorder
@@ skipping 28 matching lines @@
     TransformedCoordsArray childCoords;
     TextureSamplerArray childSamplers;
     if (childProc.numTransforms() > 0) {
         childCoords.push_back_n(childProc.numTransforms(), &args.fCoords[firstCoordAt]);
     }
     if (childProc.numTextures() > 0) {
         childSamplers.push_back_n(childProc.numTextures(), &args.fSamplers[firstSamplerAt]);
     }
 
     // emit the code for the child in its own scope
-    fb->codeAppendf("vec4 %s;\n", outputColor->c_str());
     fb->codeAppend("{\n");
     fb->codeAppendf("// Child Index %d (mangle: %s): %s\n", childIndex,
                     fb->getMangleString().c_str(), childProc.name());
     EmitArgs childArgs(args.fBuilder,
                        childProc,
-                       outputColor->c_str(),
+                       outputColor,
                        inputColor,
                        childCoords,
                        childSamplers);
     this->childProcessor(childIndex)->emitCode(childArgs);
     fb->codeAppend("}\n");
 
     fb->onAfterChildProcEmitCode();
 }