Fix memory leaks in media_bench.
Fix memory leaks in media_bench.

BUG=25855,25945
TEST=valgrind should report no leaks caused by media_bench itself

Review URL: http://codereview.chromium.org/332038


git-svn-id: http://src.chromium.org/svn/trunk/src@30228 4ff67af0-8c30-449e-8e8b-ad334ec8d88c

Former-commit-id: 8320491f46bab1988c9f3ef8690165b346f2cc1f
meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser,meego-tablet-ux/meego-app-browser