Removing the dependency on GraphicsContext for drawing images in 2D canvas

Source/platform/graphics/Image.h

Index: Source/platform/graphics/Image.h
diff --git a/Source/platform/graphics/Image.h b/Source/platform/graphics/Image.h
index 9ce321aecd348438217877392990d2074ade5be6..838de7e3bb5be7915feeb18cb0e7ea1931a67373 100644
--- a/Source/platform/graphics/Image.h
+++ b/Source/platform/graphics/Image.h
@@ -33,7 +33,7 @@
 #include "platform/graphics/GraphicsTypes.h"
 #include "platform/graphics/ImageAnimationPolicy.h"
 #include "platform/graphics/ImageOrientation.h"
-#include "third_party/skia/include/core/SkXfermode.h"
+#include "third_party/skia/include/core/SkCanvas.h"
 #include "wtf/Assertions.h"
 #include "wtf/PassRefPtr.h"
 #include "wtf/RefCounted.h"
@@ -52,10 +52,19 @@ class FloatSize;
 class GraphicsContext;
 class Length;
 class SharedBuffer;
+class Image;
 
 // This class gets notified when an image creates or destroys decoded frames and when it advances animation frames.
 class ImageObserver;
 
+class ImageFilterQualityHelper {
+public:
+    virtual SkFilterQuality computeFilterQuality(Image*, const FloatRect& dest, const FloatRect& src) const = 0;
+    virtual bool shouldClampToSourceRect() const = 0;
+    virtual bool shouldDrawAntiAliased(const FloatRect&destRect) const = 0;
+    virtual ~ImageFilterQualityHelper() { }
+};
+
 class PLATFORM_EXPORT Image : public RefCounted<Image> {
     friend class GeneratedImage;
     friend class CrossfadeGeneratedImage;
@@ -70,6 +79,8 @@ public:
 
     virtual bool isSVGImage() const { return false; }
     virtual bool isBitmapImage() const { return false; }
+    virtual bool isLazyDecodedBitmap() { return false; }
+    virtual bool isImmutableBitmap() { return false; }
     virtual bool currentFrameKnownToBeOpaque() = 0;
 
     virtual PassRefPtr<SkImage> skImage();
@@ -138,13 +149,14 @@ public:
     virtual bool notSolidColor() { return true; }
 #endif
 
+    virtual void draw(SkCanvas*, const SkPaint&, const FloatRect& dstRect, const FloatRect& srcRect, RespectImageOrientationEnum, const ImageFilterQualityHelper*) = 0;

[Stephen White, 2015/05/27 15:46:02]

To be honest, I'm not a fan of this callback object. I'd really prefer if we
could pass in some dumb state (SkPaint plus additional struct or params?). Maybe
I'm being optimistic, but it seems strange that we can't infer the desired
behaviour from passed-in state combined with specialization in the draw()
virtual on each Image subclass.

+
 protected:
     Image(ImageObserver* = 0);
 
     static void fillWithSolidColor(GraphicsContext*, const FloatRect& dstRect, const Color&, SkXfermode::Mode);
     static FloatRect adjustForNegativeSize(const FloatRect&); // A helper method for translating negative width and height values.
 
-    virtual void draw(GraphicsContext*, const FloatRect& dstRect, const FloatRect& srcRect, SkXfermode::Mode, RespectImageOrientationEnum) = 0;
     void drawTiled(GraphicsContext*, const FloatRect& dstRect, const FloatPoint& srcPoint, const FloatSize& tileSize,
         SkXfermode::Mode, const IntSize& repeatSpacing);
     void drawTiled(GraphicsContext*, const FloatRect& dstRect, const FloatRect& srcRect, const FloatSize& tileScaleFactor, TileRule hRule, TileRule vRule, SkXfermode::Mode);