Bug 997014 - Part 1: Improve GetSurfaceSnapshot. r=roc
Bug 997014 - Part 2: Make SurfaceFromElement use GetSurfaceSnapshot instead of the external API. r=roc
Bug 997014 - Part 3: Stop using the external Canvas API in nsBaseDragService. r=roc
Bug 997014 - Part 4: Remove the external canvas API. r=roc
Bug 997014 - Part 5: Remove nsICanvasRenderingContextInternal::Render. r=roc
Bug 997014 - Part 6: Remove duplicate code for retreiving a snapshot from a canvas in CanvasRenderingContext2D. r=roc