LOG(INFO) -> VLOG(0) in content/

Let me know if you prefer to keep some of these as INFO or just delete
them.

R=jam@chromium.org
BUG=322805

Review URL: https://codereview.chromium.org/84293002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@236936 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 236936