Move WebScreenOrientationClient to WebFrameClient.

Requested by jam@, because of WebViewClient being doomed to a painful death.

BUG=162827

Review URL: https://codereview.chromium.org/319633007

git-svn-id: svn://svn.chromium.org/blink/trunk@175923 bbb929c8-8fbe-4397-9dbb-9b2b20218538