Use child processors to implement compose color filter.

src/effects/SkColorCubeFilter.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 "SkColorCubeFilter.h"
 #include "SkColorPriv.h"
 #include "SkOnce.h"
@@ skipping 142 matching lines @@
 void SkColorCubeFilter::toString(SkString* str) const {
     str->append("SkColorCubeFilter ");
 }
 #endif
 
 ///////////////////////////////////////////////////////////////////////////////
 #if SK_SUPPORT_GPU
 
 class GrColorCubeEffect : public GrFragmentProcessor {
 public:
-    static GrFragmentProcessor* Create(GrTexture* colorCube) {
+    static const GrFragmentProcessor* Create(GrTexture* colorCube) {
         return (nullptr != colorCube) ? new GrColorCubeEffect(colorCube) : nullptr;
     }
 
     virtual ~GrColorCubeEffect();
 
     const char* name() const override { return "ColorCube"; }
 
     int colorCubeSize() const { return fColorCubeAccess.getTexture()->width(); }
 
 
@@ skipping 122 matching lines @@
     const GrColorCubeEffect& colorCube = proc.cast<GrColorCubeEffect>();
     SkScalar size = SkIntToScalar(colorCube.colorCubeSize());
     pdman.set1f(fColorCubeSizeUni, SkScalarToFloat(size));
     pdman.set1f(fColorCubeInvSizeUni, SkScalarToFloat(SkScalarInvert(size)));
 }
 
 void GrColorCubeEffect::GLProcessor::GenKey(const GrProcessor& proc,
                                             const GrGLSLCaps&, GrProcessorKeyBuilder* b) {
 }
 
-bool SkColorCubeFilter::asFragmentProcessors(GrContext* context, GrProcessorDataManager*,
-                                             SkTDArray<const GrFragmentProcessor*>* array) const {
+const GrFragmentProcessor* SkColorCubeFilter::asFragmentProcessor(GrContext* context,
+                                                                  GrProcessorDataManager*) const {
     static const GrUniqueKey::Domain kDomain = GrUniqueKey::GenerateDomain();
     GrUniqueKey key;
     GrUniqueKey::Builder builder(&key, kDomain, 2);
     builder[0] = fUniqueID;
     builder[1] = fCache.cubeDimension();
     builder.finish();
 
     GrSurfaceDesc desc;
     desc.fWidth = fCache.cubeDimension();
     desc.fHeight = fCache.cubeDimension() * fCache.cubeDimension();
     desc.fConfig = kRGBA_8888_GrPixelConfig;
 
     SkAutoTUnref<GrTexture> textureCube(
         context->textureProvider()->findAndRefTextureByUniqueKey(key));
     if (!textureCube) {
         textureCube.reset(context->textureProvider()->createTexture(
             desc, true, fCubeData->data(), 0));
         if (textureCube) {
             context->textureProvider()->assignUniqueKeyToTexture(key, textureCube);
+        } else {
+            return nullptr;
         }
     }
 
-    GrFragmentProcessor* frag = textureCube ? GrColorCubeEffect::Create(textureCube) : nullptr;
-    if (frag) {
-        if (array) {
-            *array->append() = frag;
-        } else {
-            frag->unref();
-            SkDEBUGCODE(frag = nullptr;)
-        }
-        return true;
-    }
-    return false;
+    return GrColorCubeEffect::Create(textureCube);
 }
 #endif