Supporting blob urls for html5 media

Android mediaplayer won't be able to handle blob urls.
After xhr requests creates a temporary file with blob url, we need to pass the file path to the media player so it can play the file.

TBR=tedchoc
BUG=253465

Review URL: https://codereview.chromium.org/98823003

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@245108 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 245108