Move UILayoutTest.MediaUILayoutTest valgrind suppression into shared suppressions file.

BUG=53825
TEST=should still be suppressed
TBR=timurrrr

Review URL: http://codereview.chromium.org/6897047

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@82873 0039d316-1c4b-4281-b951-d872f2087c98