Fixed license overflow in about:credits

BUG=246931

Review URL: https://chromiumcodereview.appspot.com/15924013

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@224703 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 224703
Tootlips for the OSX App Launcher grid.

Currently Apps with a long name get truncated in the app launcher grid,
and the full name is not revealable. Also r219761 introduced a new
short_name manifest property to give apps more control over the name
that appears in the app launcher. If the app specifies a distinct
short_name, or the name is truncated, the full name of the app should be
shown in a tooltip.

Turns out Cocoa is pretty smart about tooltop hit tests, and shows
tooltips even for views that return nil from hitTest:(NSPoint). This
makes it easy to add a tooltip for grid items, just by setting the
tooltip for the background view for the grid buttons.

BUG=271803
TEST=Have an App Launcher on OSX with long names, which are tuncated
with an ellipsis. A tooltip should be shown for these items. Names that
fit should not get a tooltip.

Review URL: https://chromiumcodereview.appspot.com/23537050

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@224704 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 224704