hang in mediaSelectionGroupForMediaCharacteristic
https://bugs.webkit.org/show_bug.cgi?id=114054

Reviewed by Eric Carlson.

No new tests; Fixes sporadic hangs in media/ tests.

-[AVURLAsset mediaSelectionGroupForMediaCharacteristic:] can deadlock in certain situations: When AVURLAsset
posts a synchronous AVAssetResourceLoader notification to the main thread, calling -mediaSelectionGroupForMediaCharacteristic:
on the main thread requires IO to occur if the media characteristics are not yet loaded. Instead of blocking,
bail out early if the media characteristics are not yet known.

Add a new method, safeMediaSelectionGroupForLegibleMedia(), which first checks selection group availability
before calling mediaSelectionGroupForMediaCharacteristic:.

* platform/graphics/avfoundation/objc/MediaPlayerPrivateAVFoundationObjC.h:
(MediaPlayerPrivateAVFoundationObjC):
* platform/graphics/avfoundation/objc/MediaPlayerPrivateAVFoundationObjC.mm:
(WebCore::MediaPlayerPrivateAVFoundationObjC::safeMediaSelectionGroupForLegibleMedia): Added.
(WebCore::MediaPlayerPrivateAVFoundationObjC::createAVPlayerItem): Use new safe method.
(WebCore::MediaPlayerPrivateAVFoundationObjC::tracksChanged): Ditto.
(WebCore::MediaPlayerPrivateAVFoundationObjC::processTextTracks): Ditto.
(WebCore::MediaPlayerPrivateAVFoundationObjC::setCurrentTrack): Ditto.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@148064 268f45cc-cd09-0410-ab3c-d52691b4dbfc
REGRESSION (r123837): Full screen transition is broken at apple.com
https://bugs.webkit.org/show_bug.cgi?id=95650

Reviewed by Simon Fraser.

Cancel any outstanding animations on <video> elements as they enter full screen, so as to
not confuse the WebKit/WebKit2 full screen window animation about the starting and destination
screen rects.

* css/fullscreen.css:
(video:-webkit-full-screen, audio:-webkit-full-screen):

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@148065 268f45cc-cd09-0410-ab3c-d52691b4dbfc