Mac: make pinned tab title change alert more noticeable.
Mac: make pinned tab title change alert more noticeable.

Make the alert glow fade in to look like a selected tab, which should be quite
visible on all themes, including the default theme (i.e., no theme).

BUG=32791
TEST=Go to <http://www.surflocal.net/Awards/submit/animatedtitle.html>, pin that tab, and create and select a new tab. Watch the pinned tab "glow" in and out quite visibly (but smoothly). Check that it behaves properly when the mouse moves over it. Check with lots of different themes.

Review URL: http://codereview.chromium.org/549144

git-svn-id: dd90618784b6a4b323ea0c23a071cb1c9e6f2ac7@36982 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser,wistoch/meego-app-browser