import changes from `dev' branch of rmottola/Arctic-Fox:

- Bug 1188569: Drop unneeded MOZ_WARN_UNUSED_RESULT from from LookupBestMatch in SurfaceCache.cpp. r=seth (5e74e0028c)
- Bug 1192356 (Part 1) - Take advantage of mozilla::Tie() in SurfaceCache.cpp. r=dholbert (e4908c725d)
- Bug 1192356 (Part 2) - Take advantage of mozilla::Tie() in RasterImage.cpp. r=tn (1204189b73)
- Bug 1185800 - Add DecoderFlags and SurfaceFlags enum classes and use them instead of imgIContainer flags in all decoder-related code. r=tn (3abdab11f6)
- Bug 1196066 (Part 3) - Rewrite nsICODecoder to use StreamingLexer. r=tn (e2ba590c9d)
- Bug 1196066 (Part 4) - Enable the ICOMultiChunk test, which now passes. r=tn (9e02611959)
- Bug 1124084 - Flip on downscale-during-decode everywhere. r=tn (bd9deff966)
- Bug 1160801 - Treat invalid GIF disposal methods as DisposalMethod::NOT_SPECIFIED. r=jrmuizel (e26feaf8fb)
- Bug 1201796 (Part 1) - Treat ICOs with wrong widths and heights as corrupt. r=tn (322ba20808)
- Bug 1201796 (Part 2) - Add GetFrameAtSize() to support downscale-during-decode for GetFrame() use cases. r=tn (92f5d3a0a7)
- Bug 1194906 - Replace 'NS_ENSURE_TRUE(BadImage(..))' warnings with more useful messages. r=tn (cc3b368673)
- Bug 1201796 (Part 3) - Enable downscale-during-decode for imgITools::EncodeScaledImage(). r=tn (e2cdb5b520)
- Bug 1194472 - Correctly fetch compositor backend in WebGLContext. r=jgilbert (0092052dfc)
- Bug 1161913 - Part 1 - Add invalidation state for CaptureStream to Canvas and Contexts. r=mt (0377d6bbe7)
- Bug 1168075 - Fix CanvasCaptureMediaStream build fail for bluetooth2. r=pehrsons (53c67c0056)
- Bug 1176363 - Part 1: Make a raw copy of each Canvas::CaptureStream frame. r=mattwoodrow (a5df5793d6)
- Bug 1194575 - Rename RecoverFromLossOfFrames() to RecoverFromInvalidFrames() to better reflect its role. r=tn (baa6455e79)
- Bug 1146663 (Part 1) - Remove HQ scaling, which is now dead code. r=tn (efaddadea0)
- Bug 1146663 (Part 2) - Remove the concept of lifetimes from the SurfaceCache. r=dholbert (ab9862d7ee)
- Bug 1146663 (Part 3) - Make it impossible to deoptimize imgFrames. r=tn (19e2f1b370)
- Bug 1201763 - Add downscale-during-decode support for the ICON decoder. r=tn (33a2b95e5c)
- Bug 1194058 (Part 1) - Add Deinterlacer to allow Downscaler to work with interlaced images. r=tn (f7c57b7a8e)
- Bug 1194058 (Part 2) - Add downscale-during-decode support for the GIF decoder. r=tn (85622f9d55)
- Bug 1201796 (Part 4) - Add downscale-during-decode support for the ICO decoder. r=tn (d09d18b0d9)
- Bug 1146663 (Part 4) - Make all RasterImages support downscale-during-decode. r=tn (264642a895)
- Bug 1146663 (Part 5) - Require that all image decoders support downscale-during-decode. r=tn (79ad99885d)
- Bug 1206836 - When downscaling ICOs, downscale the AND mask as well. r=tn a=KWierso (08ec3d092b)
- missing bit of Bug 1138293 - Use malloc/free/realloc/calloc (eb8e5e1b9c)
- missing bit of Bug 1146663 (Part 3) - Make it impossible to deoptimize imgFrames. (233befe48f)
- Bug 1208935 - Move Deinterlacer to a standalone file. r=seth (b50322abc286)

image/DynamicImage.cpp

@@ -168,10 +168,18 @@ DynamicImage::GetFrame(uint32_t aWhichFrame,
                        uint32_t aFlags)
 {
   gfxIntSize size(mDrawable->Size());
+  return GetFrameAtSize(IntSize(size.width, size.height),
+                        aWhichFrame,
+                        aFlags);
+}
 
+NS_IMETHODIMP_(already_AddRefed<SourceSurface>)
+DynamicImage::GetFrameAtSize(const IntSize& aSize,
+                             uint32_t aWhichFrame,
+                             uint32_t aFlags)
+{
   RefPtr<DrawTarget> dt = gfxPlatform::GetPlatform()->
-    CreateOffscreenContentDrawTarget(IntSize(size.width, size.height),
-                                     SurfaceFormat::B8G8R8A8);
+    CreateOffscreenContentDrawTarget(aSize, SurfaceFormat::B8G8R8A8);
   if (!dt) {
     gfxWarning() <<
       "DynamicImage::GetFrame failed in CreateOffscreenContentDrawTarget";
@@ -179,7 +187,7 @@ DynamicImage::GetFrame(uint32_t aWhichFrame,
   }
   nsRefPtr<gfxContext> context = new gfxContext(dt);
 
-  auto result = Draw(context, size, ImageRegion::Create(size),
+  auto result = Draw(context, aSize, ImageRegion::Create(aSize),
                      aWhichFrame, GraphicsFilter::FILTER_NEAREST,
                      Nothing(), aFlags);