[SiteChip] Add the basic painting of the site chip button.

R=pkasting@chromium.org
BUG=315944

Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=238732

Review URL: https://codereview.chromium.org/75873002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@238890 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 238890