Bug 975468 - Allow only one NSColorPanelWrapper to be opened at a time, and retarget the existing one if user clicks on another input type color. r=areinald
Bug 978163 - Part 1: Remove VTTRegionList and VTTRegion TextTrack extensions. r=rillian, r=bz

- These two parts of the spec were recently removed as they
were seen as unecessary or bad design, in the case of the
VTTRegion TextTrack extensions. See the spec bug at:
https://www.w3.org/Bugs/Public/show_bug.cgi?id=24380
Bug 978163 - Part 2: VTTCue should have Region property. r=rillian, r=bz

See spec bug: https://www.w3.org/Bugs/Public/show_bug.cgi?id=24380
Bug 978163 - Part 3: Vtt.js should add VTTRegions directly to the VTTCue. r=rillian

See spec bug https://www.w3.org/Bugs/Public/show_bug.cgi?id=24380.
Bug 978173 - Part 4: Add test for VTTCue::Region. r=rillian

Updated test_texttrackregion.html to reflect the changes as well.

See spec bug: https://www.w3.org/Bugs/Public/show_bug.cgi?id=24380