GitLab

- Change launcher background alpha from 128 (0.5) to 204 (0.8);
- Export the background alpha const and get rid of a dup const in overflow bubble;

BUG=137309
TEST=Verify launcher background is 0.8 black.


Review URL: https://chromiumcodereview.appspot.com/10827202

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@150461 0039d316-1c4b-4281-b951-d872f2087c98