[rAc Android dialog] Edit/Add as in the latest UI mocks.
- Removes hardcoded "Add..." and "Edit..." menu items.
- Adds an "Edit" button to editable items in a drop-down.
- Removes our own strings and uses those provided by the controller.
(We could change the controller strings through .grd per platform.)
- Handles "Edit" button clicks.
- Pulls back the edited data into the presentable menu item.
UI mocks (option B):
https://docs.google.com/a/google.com/document/d/15USYTwRRhbDQRdbA1JpmWs53opL8864cwt9ETCLCFKM/edit#heading=h.n459ql1no01k
Follow-up bugs: 224162 (IsMenuItemEditable), 230685 (collapse user input).
BUG=224162, 225551, 225554, 236437
Review URL: https://chromiumcodereview.appspot.com/
14061013
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@197138 0039d316-1c4b-4281-b951-d872f2087c98