Use WebPermissionClient fom WebFrame if it has it set.

BUG=304341
R=jochen@chromium.org

Review URL: https://codereview.chromium.org/111433004

git-svn-id: svn://svn.chromium.org/blink/trunk@163901 bbb929c8-8fbe-4397-9dbb-9b2b20218538