Don't cast WebWidget to WebFrameWidget if RenderWidget is frozen.

When frozen there is no WebFrameWidget, so this cast is invalid.

R=dcheng@chromium.org

Change-Id: I7a103aeeeb9920d128e1b8ad0b6075fc830ca0d6
Bug: 920952, 917907
Reviewed-on: https://chromium-review.googlesource.com/c/1407038
Reviewed-by: Avi Drissman <avi@chromium.org>
Commit-Queue: danakj <danakj@chromium.org>
Cr-Commit-Position: refs/heads/master@{#622080}
1 file changed