Avoid GPU readback in tex(Sub)Image2D(ImageBitmap)

third_party/WebKit/Source/core/frame/ImageBitmap.h

Index: third_party/WebKit/Source/core/frame/ImageBitmap.h
diff --git a/third_party/WebKit/Source/core/frame/ImageBitmap.h b/third_party/WebKit/Source/core/frame/ImageBitmap.h
index 102232a3b496cb80c1571df51ed04b74005d27da..7e7de12b6764a0b07e308bcbac6e02b27576aa75 100644
--- a/third_party/WebKit/Source/core/frame/ImageBitmap.h
+++ b/third_party/WebKit/Source/core/frame/ImageBitmap.h
@@ -59,6 +59,7 @@ public:
     bool isPremultiplied() const { return m_image->isPremultiplied(); }
     PassRefPtr<StaticBitmapImage> transfer();
     void close();
+    bool isTextureBacked() const;
 
     ~ImageBitmap() override;
 
@@ -68,6 +69,8 @@ public:
     void adjustDrawRects(FloatRect* srcRect, FloatRect* dstRect) const override;
     FloatSize elementSize(const FloatSize&) const override;
     bool isImageBitmap() const override { return true; }
+    int sourceWidth() override { return m_image ? m_image->width() : 0; }
+    int sourceHeight() override { return m_image ? m_image->height() : 0; }
 
     // ImageBitmapSource implementation
     IntSize bitmapSourceSize() const override { return size(); }