Make WebWidget methods on WebView private.

Callers should go through WebView's MainFrameWidget() to get to them.
While WebViewImpl inherits privately from WebWidget, the overrides of
its methods were all public. This moves them to the private section
with the single exception of GetPagePopup(). This method probably
belongs on WebView, but WebViewImpl changes its return type, so it's
harder to simply move mechanically. A TODO is left for that one.

This change is mechanical and not opinionated. All callers that failed
to compile are simply switched to call MainFrameWidget()-> in order to
get to the methods.

Change-Id: I44cb270a97f3a4034f00c00631dad8631678ef53
Bug: 912193
Reviewed-by: Daniel Cheng <>
Commit-Queue: danakj <>
Cr-Commit-Position: refs/heads/master@{#614479}
47 files changed