JPEGImageDecoder RGB565 and downsample support and related Skia imagegenerator changes

third_party/WebKit/Source/platform/image-decoders/ImageFrame.h

Index: third_party/WebKit/Source/platform/image-decoders/ImageFrame.h
diff --git a/third_party/WebKit/Source/platform/image-decoders/ImageFrame.h b/third_party/WebKit/Source/platform/image-decoders/ImageFrame.h
index fb7425755bd77887066531b171c6c8dc21c5b2d8..9566a6e4fe98ea4aac2349697cf8f034ec580fa3 100644
--- a/third_party/WebKit/Source/platform/image-decoders/ImageFrame.h
+++ b/third_party/WebKit/Source/platform/image-decoders/ImageFrame.h
@@ -66,7 +66,14 @@ public:
         // overwrite the corresponding pixels).
         BlendAtopBgcolor,
     };
+
+    enum ColorType {
+        RGBA8888 = kN32_SkColorType,
+        RGB565 = kRGB_565_SkColorType
+    };
+
     typedef uint32_t PixelData;
+    typedef uint16_t PixelData16;
 
     ImageFrame();
 
@@ -107,9 +114,13 @@ public:
     }
 
     // Allocates space for the pixel data.  Must be called before any pixels
-    // are written.  Must only be called once.  Returns whether allocation
-    // succeeded.
-    bool setSize(int newWidth, int newHeight);
+    // are written. Returns whether allocation succeeded.
+    bool setSize(int newWidth, int newHeight, ColorType bitmapType = RGBA8888);
+    inline bool hasSize(const IntSize& size, ColorType bitmapType) const
+    {
+        // skip checking height, no stretching involved
+        return (m_bitmap.width() == size.width()) && (bitmapType == static_cast<ColorType>(m_bitmap.colorType()));
+    }
 
     // Returns a caller-owned pointer to the underlying native image data.
     // (Actual use: This pointer will be owned by BitmapImage and freed in
@@ -146,6 +157,12 @@ public:
         return m_bitmap.getAddr32(x, y);
     }
 
+    template<class T>
+    inline T* getAddrT(int x, int y)
+    {
+        ASSERT_NOT_REACHED();
+    }
+
     inline void setRGBA(int x, int y, unsigned r, unsigned g, unsigned b, unsigned a)
     {
         setRGBA(getAddr(x, y), r, g, b, a);
@@ -178,6 +195,11 @@ public:
         *dest = SkPackARGB32NoCheck(a, r, g, b);
     }
 
+    static inline void setRGB565(PixelData16* dest, unsigned r, unsigned g, unsigned b)
+    {
+        *dest = SkDitherPack888ToRGB16(r, g, b);
+    }
+
     // Notifies the SkBitmap if any pixels changed and resets the flag.
     inline void notifyBitmapIfPixelsChanged()
     {
@@ -218,6 +240,18 @@ private:
     size_t m_requiredPreviousFrameIndex;
 };
 
+template<>
+inline ImageFrame::PixelData* ImageFrame::getAddrT<ImageFrame::PixelData>(int x, int y)
+{
+    return m_bitmap.getAddr32(x, y);
+}
+
+template<>
+inline ImageFrame::PixelData16* ImageFrame::getAddrT<ImageFrame::PixelData16>(int x, int y)
+{
+    return m_bitmap.getAddr16(x, y);
+}
+
 } // namespace blink
 
 #endif