Bug 749118 - Translate the source correctly in RasterImage::CopyFrame. r=joe

image/src/RasterImage.cpp

@@ -851,8 +851,9 @@ RasterImage::CopyFrame(PRUint32 aWhichFrame,
                                                              gfxASurface::ImageFormatARGB32);
   gfxContext ctx(imgsurface);
   ctx.SetOperator(gfxContext::OPERATOR_SOURCE);
-  ctx.SetPattern(pattern);
   ctx.Rectangle(framerect);
+  ctx.Translate(framerect.TopLeft());
+  ctx.SetPattern(pattern);
   ctx.Fill();
 
   *_retval = imgsurface.forget().get();