[Android] Clean up TODO's post r225480

Downstream dependencies have been resolved after
https://codereview.chromium.org/23672055/ landed.

BUG=

Review URL: https://codereview.chromium.org/24854002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@226188 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 226188