Fix the PlatformAppBrowserTest.MutationEventsDisabled browser_test when getting WebPermissionClient from the WebFrame.
Fix the PlatformAppBrowserTest.MutationEventsDisabled browser_test when getting WebPermissionClient from the WebFrame.

My chrome-side change https://codereview.chromium.org/104833006/ exposed this bug.

BUG=304341
R=japhet@chromium.org

Review URL: https://codereview.chromium.org/113453008

git-svn-id: bf5cd6ccde378db821296732a091cfbcf5285fbd@163991 bbb929c8-8fbe-4397-9dbb-9b2b20218538

primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs,primiano/blink-gitcs