Remove unused methods from MediaPlayerClient
https://bugs.webkit.org/show_bug.cgi?id=136884

Reviewed by Eric Carlson.

Remove unused methods from MediaPlayerClient that introduce
dependencies on WebCore types.

* html/HTMLMediaElement.cpp:
* html/HTMLMediaElement.h:
* platform/graphics/MediaPlayer.h:
(WebCore::MediaPlayerClient::mediaPlayerOwningDocument): Deleted.
(WebCore::MediaPlayerClient::mediaPlayerHostWindow): Deleted.
(WebCore::MediaPlayerClient::mediaPlayerWindowClipRect): Deleted.

git-svn-id: http://svn.webkit.org/repository/webkit/trunk@173719 268f45cc-cd09-0410-ab3c-d52691b4dbfc