Remove unused implementations in WebInbandTextTrackImpl

These functions have been removed from WebInbandTextTrack.

BUG=315257, 315270, 315476

Review URL: https://codereview.chromium.org/63963002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@233835 0039d316-1c4b-4281-b951-d872f2087c98
Refactor taskbar anchor calculations in app_list_win.

Cleanly separates the concerns of determining which edge the taskbar
is pinned to, and finding the reference point for the given edge.

Also makes several implicit assumptions into explicit checks. For
example, before if a horizontal taskbar was not at the bottom, it was
assumed to be at the top. Now we check that it is at the top, and if
not, fall back on the default. This new behaviour should not be
visible, but if the taskbar is in an unexpected place, it should fail
gracefully.

BUG=307837

Review URL: https://codereview.chromium.org/63983002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@233836 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 233835
SVN changes up to revision 233836