TextAutosizer should handle frames without a FrameView.

During cross-process navigation, it is possible to create a LocalFrame
that doesn't have a FrameView, since the latter gets created at the time
a document commits. Since the commit in this case happens later in time,
the current code crashes as it expects the view to be there.

BUG=357747

Review URL: https://codereview.chromium.org/1374783005

Cr-Commit-Position: refs/heads/master@{#351204}
1 file changed