Update Android IPC messages to EME WD

EME implementation now supports EME WD, so update the Android IPC messages
to match the method names used in EME WD. Also adds in the additional
callback SessionClosed.

TEST=browser_tests for encrypted media pass
BUG=224786

Review URL: https://codereview.chromium.org/100323004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@240016 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 240016