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* Properly enable and disable the Edit and Remove buttons based on select
control state.
* Modify the title of the address/CC overlays when pressing the
'Add address/CC' buttons.
* Remove the ability to select multiple options.

BUG=49094
TEST=none

Review URL: http://codereview.chromium.org/3125039

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@57129 0039d316-1c4b-4281-b951-d872f2087c98