Revert 167841 "Revert 167826 "Rename text track methods to make ..."

This is a revert of the revert. r167826 was not a culprit of the test breakage in Linux bots.

> Revert 167826 "Rename text track methods to make way for audio &..."
> 
> This CL broke a lot of Media tests and Track tests in Linux bots.
> http://build.chromium.org/p/chromium.webkit/builders/WebKit%20Linux%2032
> 
> > Rename text track methods to make way for audio & video tracks.
> > 
> > - Rename various text track related methods to explicitly indicate that
> >   they apply to text tracks. This is to avoid confusion when audio &
> >   video track logic is landed.
> > 
> > - Renamed TextTrackList::clearOwner() to clearOwnerAndClients() and moved
> >   some the client clearing out of HTMLMediaElement and into TextTrackList.
> >   This doesn't introduce any change in behavior. It just restores some
> >   encapsulation.
> > 
> > BUG=249427
> > TEST=All LayoutTests still pass.
> > 
> > Review URL: https://codereview.chromium.org/180173002
> 
> TBR=acolwell@chromium.org
> 
> Review URL: https://codereview.chromium.org/177213015

TBR=haraken@chromium.org

Review URL: https://codereview.chromium.org/176943005

git-svn-id: svn://svn.chromium.org/blink/trunk@167842 bbb929c8-8fbe-4397-9dbb-9b2b20218538