Reland r256032 "Clean up usage of MediaCodecBridge/MediaDrmBridge::IsAvailable()".

Fixed VLOG include errors in the original CL.

Description of the original CL:

- All static methods in MediaCodecBridge and MediaDrmBridge check IsAvailable()
  internally so that callers don't need to check IsAvailable() before calling
  these static methods.
- Remove MediaSourcePlayer::IsTypeSupported() because it's obsolete now.
- Add MediaDrmBridge unittests.

BUG=303864
TBR=ddorwin@chromium.org,qinmin@chromium.org

Review URL: https://codereview.chromium.org/193353002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@256192 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 256192