[rAC, OSX] Add tooltip/icon to "Save in Chrome"

BUG=286532
R=isherman@chromium.org

Review URL: https://codereview.chromium.org/28923008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230193 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 230193
Some unit tests.

I started to develop unit tests for merging cards, but then switched to other stuff. I don't want the added code to rotten on my machine, so I'm submitting it. Later, I'll add more tests.

BUG=164227
TEST=No

Review URL: https://codereview.chromium.org/32583004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@230194 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 230194