Delete the StatisticsCallback passed to media filter mocks.
Delete the StatisticsCallback passed to media filter mocks.

Patch by sjl@chromium.org:
http://codereview.chromium.org/6519024/

BUG=73132
TEST=media_unittests under heapcheck and valgrind to make sure the new leak has gone.

git-svn-id: dd90618784b6a4b323ea0c23a071cb1c9e6f2ac7@75222 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