Refactoring ImageBuffer to decouple it from Canvas2DLayerBridge

Source/core/svg/graphics/SVGImage.cpp

Index: Source/core/svg/graphics/SVGImage.cpp
diff --git a/Source/core/svg/graphics/SVGImage.cpp b/Source/core/svg/graphics/SVGImage.cpp
index 9dbf716e0ecafe03a264f43d8239bc71dcf0b9f6..0a844dd02c3cd11da4306773e84f882ce8a6dd8c 100644
--- a/Source/core/svg/graphics/SVGImage.cpp
+++ b/Source/core/svg/graphics/SVGImage.cpp
@@ -192,8 +192,8 @@ PassRefPtr<NativeImageSkia> SVGImage::nativeImageForCurrentFrame()
     if (!m_page)
         return 0;
 
-    OwnPtr<ImageBuffer> buffer = ImageBuffer::create(size(), 1);
-    if (!buffer) // failed to allocate image
+    OwnPtr<ImageBuffer> buffer = ImageBuffer::create(size());
+    if (!buffer)
         return 0;
 
     drawForContainer(buffer->context(), size(), 1, rect(), rect(), CompositeSourceOver, blink::WebBlendModeNormal);
@@ -220,9 +220,10 @@ void SVGImage::drawPatternForContainer(GraphicsContext* context, const FloatSize
     FloatRect imageBufferSize = zoomedContainerRect;
     imageBufferSize.scale(imageBufferScale.width(), imageBufferScale.height());
 
-    OwnPtr<ImageBuffer> buffer = ImageBuffer::create(expandedIntSize(imageBufferSize.size()), 1);
+    OwnPtr<ImageBuffer> buffer = ImageBuffer::create(expandedIntSize(imageBufferSize.size()));
     if (!buffer) // Failed to allocate buffer.
         return;
+
     drawForContainer(buffer->context(), containerSize, zoom, imageBufferSize, zoomedContainerRect, CompositeSourceOver, blink::WebBlendModeNormal);
     RefPtr<Image> image = buffer->copyImage(DontCopyBackingStore, Unscaled);