Always mark cross-origin as true for regular media urls

      We cannot guarantee that urls will not be redirected when android mediaplayer requests video streams.
Always treat media urls as cross-origin for now.

BUG=334204

Review URL: https://codereview.chromium.org/247573004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@266396 0039d316-1c4b-4281-b951-d872f2087c98