GitLab

Remove RootView::DispatchGestureEvent() and instead
call up to the unified event processing logic in
EventProcessor::OnEventFromSource(). This CL
also introduces the virtual method
EventProcessor::OnEventProcessingFinished(),
which is called when the processing of an
event is finished.

BUG=404234
TEST=EventProcessorTest.OnEventProcessingFinished

Review URL: https://codereview.chromium.org/533323004

Cr-Commit-Position: refs/heads/master@{#294249}