Skia side RGB to YUV gpu conversion

include/core/SkImageGenerator.h

Index: include/core/SkImageGenerator.h
diff --git a/include/core/SkImageGenerator.h b/include/core/SkImageGenerator.h
index 157bfdb0010646cc7e82d70466a2d4bbf9fd2d62..870afbfe80d674e4f40ac5fd73b12f7d1eed336d 100644
--- a/include/core/SkImageGenerator.h
+++ b/include/core/SkImageGenerator.h
@@ -116,12 +116,23 @@ public:
     bool getPixels(const SkImageInfo& info, void* pixels, size_t rowBytes);
 #endif
 
+    /**
+     *  If planes is NULL, this imagegenerator should output the sizes and return true
+     *  if it can efficiently return YUV planar data. If it cannot, it should return false.
+     *
+     *  If planes is not NULL, then it should copy the associated Y,U,V data into those planes
+     *  of memory supplied by the caller. It should validate that the sizes match what it expected.
+     *  If the sizes do not match, it should return false.
+     */
+    bool getYUV8Planes(SkISize* sizes, void* planes);
+
 protected:
     virtual SkData* onRefEncodedData();
     virtual bool onGetInfo(SkImageInfo* info);
     virtual bool onGetPixels(const SkImageInfo& info,
                              void* pixels, size_t rowBytes,
                              SkPMColor ctable[], int* ctableCount);
+    virtual bool onGetYUV8Planes(SkISize*, void*);
 };
 
 #endif  // SkImageGenerator_DEFINED