Followup to r230789 to make BrowserMediaPlayerManager owned by RenderViewHostImpl. I had changed this file but forgot to put it in the same cl. Right now the BrowserMediaPlayerManager is leaked because a RenderViewHostObserver deletes itself, while a WebContentsObserver doesn't.

BUG=306569
R=qinmin@chromium.org

Review URL: https://codereview.chromium.org/44463003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@231054 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 231054
Fix crash when ExitFullscreen is called during shutdown.

BUG=311331
R=dtrainor@chromium.org

Review URL: https://codereview.chromium.org/42623002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@231055 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 231055