Bug 884275 - Report 'maybe' instead of 'probably' from canPlayType('video/webm'). r=rillian
Bug 921215 - Handle being passed NULL ptr for either surface or gl to SharedSurface_IOSurface::Create by returning NULL. r=mattwoodrow
Bug 928675 - Don't center sub/superscripts relative to each other. r=fredw
Bug 941283 - OpusTrackEncoder should write pre-skip at the original samplerate. r=rillian
Bug 945314 - Workaround crash with Cairo surfaces in Skia backend. r=mstange

A patch for bug 924102 introduced a MOZ_CRASH assertion for surfaces
of type other than SURFACE_SKIA or SURFACE_DATA being passed to
DrawSurface. Previously surfaces of other types were simply ignored.
On Linux, there are still several hardcoded surfaces of type Cairo
(found in gfxXlibNativeRenderer and friends) and as a result, the
Skia backend crashes always on Linux currently.

This workaround ignores Cairo surfaces passed to DrawSurface.