import changes from rmottola/Arctic-Fox:

- Bug 1125750 - Check the overflow region direction to avoid unnecesary reflow for scrollable frame. (6b5067631)
- Bug 1125750 - Add auto test to detect error when using mOuter to check overflow area of a scrollable frame. (4e9c43e31)
- override -> MOZ_OVERRIDE (ed1ecc151)
- Bug 990907 - Don't add text-overflow markers while being actively scrolled by APZ. (523bc5a3e)
- Bug 945584: Part 6 - Implementation of scroll snapping (v10 Patch) (bf64eb0f3)
- Bug 945584: Part 7 - Implement Scroll Snapping for Autoscroll, - Triggering scroll snapping at the end of an autoscroll. - This enables text selection to be unencumbered by scroll snapping, while   restoring the scroll position to a valid snapping position when the drag   operation is completed. (db9ce9811)
- Bug 945584: Part 8 - Implement Scroll Snapping for Middle Mouse Button Scrolls (v2 Patch) (06d1b733d)
- some MacOS 10.5 Leopard support (6a37f6745)
- Bug 945584: Part 9 - Tests for scroll snapping (v4 Patch) (f67175387)
- Bug 1102427 - Ensure scroll parents of an active scrollframe are layerized. (910d43ec5)
- Bug 1142731 followup. Check isInterpreted() before we call environment(), because of the asmjs lambdas. (29b2acdc7)
- Bug 1161627 - part 1 - add move constructor and assignment operator for already_AddRefed&& to RefPtr; This change is prep work for future mass rewriting. (98416d45c)
- Bug 1161627 - part 2 - machine-convert TemporaryRef<T> to already_AddRefed<T>; (336e96af7)
- Bug 1161627 - part 3 - remove TemporaryRef<T> from RefPtr.h (6c3acdaed)
- Bug 940273 - Part 3 - Service Worker Cache webidl. (4b6803d0a)
- Bug 940273 - Part 4 - Initial implementation of Service Worker Cache. (74498c108)
- Bug 1133861 - Bustage fix. (4a81437c2)

gfx/layers/basic/BasicCompositor.cpp

@@ -105,7 +105,7 @@ void BasicCompositor::Destroy()
   mWidget = nullptr;
 }
 
-TemporaryRef<CompositingRenderTarget>
+already_AddRefed<CompositingRenderTarget>
 BasicCompositor::CreateRenderTarget(const IntRect& aRect, SurfaceInitMode aInit)
 {
   MOZ_ASSERT(aRect.width != 0 && aRect.height != 0, "Trying to create a render target of invalid size");
@@ -125,7 +125,7 @@ BasicCompositor::CreateRenderTarget(const IntRect& aRect, SurfaceInitMode aInit)
   return rt.forget();
 }
 
-TemporaryRef<CompositingRenderTarget>
+already_AddRefed<CompositingRenderTarget>
 BasicCompositor::CreateRenderTargetFromSource(const IntRect &aRect,
                                               const CompositingRenderTarget *aSource,
                                               const IntPoint &aSourcePoint)
@@ -134,7 +134,7 @@ BasicCompositor::CreateRenderTargetFromSource(const IntRect &aRect,
   return nullptr;
 }
 
-TemporaryRef<DataTextureSource>
+already_AddRefed<DataTextureSource>
 BasicCompositor::CreateDataTextureSource(TextureFlags aFlags)
 {
   RefPtr<DataTextureSource> result = new DataTextureSourceBasic();