GitLab

Note:
Currently FaviconTabHelper implements both FaviconClient and FaviconDriver.
A follow up CL will create a ContentFaviconDriver class that implements
FaviconDriver. FaviconTabHelper will then own an instance of the
ContentFaviconDriver, instead of inheriting from FaviconDriver.

BUG=362074

Review URL: https://codereview.chromium.org/255843002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@266551 0039d316-1c4b-4281-b951-d872f2087c98