Make swizzling in read/write pixel copy code more generic

include/gpu/GrContext.h

 /*
  * Copyright 2010 Google Inc.
  *
  * Use of this source code is governed by a BSD-style license that can be
  * found in the LICENSE file.
  */
 
 #ifndef GrContext_DEFINED
 #define GrContext_DEFINED
 
@@ skipping 25 matching lines @@
 class GrPipelineBuilder;
 class GrResourceEntry;
 class GrResourceCache;
 class GrResourceProvider;
 class GrTestTarget;
 class GrTextBlobCache;
 class GrTextContext;
 class GrTextureParams;
 class GrVertexBuffer;
 class GrStrokeInfo;
+class GrSwizzle;
 class SkTraceMemoryDump;
 
 class SK_API GrContext : public SkRefCnt {
 public:
     /**
      * Creates a GrContext for a backend context.
      */
     static GrContext* Create(GrBackend, GrBackendContext, const GrContextOptions& options);
     static GrContext* Create(GrBackend, GrBackendContext);
 
@@ skipping 366 matching lines @@
 
     GrContext(); // init must be called after the constructor.
     bool init(GrBackend, GrBackendContext, const GrContextOptions& options);
 
     void initMockContext();
     void initCommon(const GrContextOptions&);
 
     /**
      * These functions create premul <-> unpremul effects if it is possible to generate a pair
      * of effects that make a readToUPM->writeToPM->readToUPM cycle invariant. Otherwise, they
-     * return NULL.
+     * return NULL. They also can perform a swizzle as part of the draw.
      */
-    const GrFragmentProcessor* createPMToUPMEffect(GrTexture*, bool swapRAndB,
+    const GrFragmentProcessor* createPMToUPMEffect(GrTexture*, const GrSwizzle&,
                                                    const SkMatrix&) const;
-    const GrFragmentProcessor* createUPMToPMEffect(GrTexture*, bool swapRAndB,
+    const GrFragmentProcessor* createUPMToPMEffect(GrTexture*, const GrSwizzle&,
                                                    const SkMatrix&) const;
     /** Called before either of the above two functions to determine the appropriate fragment
         processors for conversions. This must be called by readSurfacePixels before a mutex is
         taken, since testingvPM conversions itself will call readSurfacePixels */
     void testPMConversionsIfNecessary(uint32_t flags);
     /** Returns true if we've already determined that createPMtoUPMEffect and createUPMToPMEffect
         will fail. In such cases fall back to SW conversion. */
     bool didFailPMUPMConversionTest() const;
 
     /**
      *  This callback allows the resource cache to callback into the GrContext
      *  when the cache is still over budget after a purge.
      */
     static void OverBudgetCB(void* data);
 
     /**
      * A callback similar to the above for use by the TextBlobCache
      * TODO move textblob draw calls below context so we can use the call above.
      */
     static void TextBlobCacheOverBudgetCB(void* data);
 
     typedef SkRefCnt INHERITED;
 };
 
 #endif