Implement InterpolationMedium to filter animated images

Source/core/html/HTMLCanvasElement.cpp

Index: Source/core/html/HTMLCanvasElement.cpp
diff --git a/Source/core/html/HTMLCanvasElement.cpp b/Source/core/html/HTMLCanvasElement.cpp
index 4ea22121fa982da6aa7d0e3754e0d820cd904e05..10e5a40a1888a5557ada143e53de838c1d74abce 100644
--- a/Source/core/html/HTMLCanvasElement.cpp
+++ b/Source/core/html/HTMLCanvasElement.cpp
@@ -303,7 +303,7 @@ bool HTMLCanvasElement::paintsIntoCanvasBuffer() const
 }
 
 
-void HTMLCanvasElement::paint(GraphicsContext* context, const LayoutRect& r, bool useLowQualityScale)
+void HTMLCanvasElement::paint(GraphicsContext* context, const LayoutRect& r, InterpolationQuality interpolationQuality)

[Stephen White, 2014/03/18 17:26:43]

I believe this is only used when compositing the canvas into the page, not while
drawing elements into the canvas (and only in software rasterization, IIRC, not
for accelerated rendering).

I'm not sure if that changes what value we pass here.

[Alpha Left Google, 2014/03/18 22:59:13]

I don't think it matters functionally. If the argument stays a boolean then I
have to do an ugly convertion from bool -> InterpolationQuality in the
drawBlah() calls. Having the enum as parameter seems cleaner.

 {
     // Clear the dirty rect
     m_dirtyRect = FloatRect();
@@ -322,9 +322,9 @@ void HTMLCanvasElement::paint(GraphicsContext* context, const LayoutRect& r, boo
         if (imageBuffer) {
             CompositeOperator compositeOperator = !m_context || m_context->hasAlpha() ? CompositeSourceOver : CompositeCopy;
             if (m_presentedImage)
-                context->drawImage(m_presentedImage.get(), pixelSnappedIntRect(r), compositeOperator, DoNotRespectImageOrientation, useLowQualityScale);
+                context->drawImage(m_presentedImage.get(), pixelSnappedIntRect(r), compositeOperator, DoNotRespectImageOrientation, interpolationQuality);
             else
-                context->drawImageBuffer(imageBuffer, pixelSnappedIntRect(r), compositeOperator, blink::WebBlendModeNormal, useLowQualityScale);
+                context->drawImageBuffer(imageBuffer, pixelSnappedIntRect(r), compositeOperator, blink::WebBlendModeNormal, interpolationQuality);
         }
     }