Remove obsolete overload of applyViewportDeltas from WebWidget API.
Remove obsolete overload of applyViewportDeltas from WebWidget API.

The remaining users on the Chromium-side were removed in r331955.

BUG=304869

Review URL: https://codereview.chromium.org/1156903003

git-svn-id: bf5cd6ccde378db821296732a091cfbcf5285fbd@196435 bbb929c8-8fbe-4397-9dbb-9b2b20218538

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