input: Change how synthesized events are dispatched in telemetry tests.
Synthesized events are still generated and dispatched on begin-frame. But
the dispatch is somewhat simplified in this change. Some detail:
. Before this change, SyntheticGestureController would request for the
next input flush through the SyntheticGestureTarget, which would then
request for flush to RenderWidgetHostImpl. This CL changes that, so that
SyntheticGestureController can directly request for flush to
RenderWidgetHostImpl, through a callback installed during construction
of SyntheticGestureController.
BUG=722921
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_site_isolation
Review-Url: https://codereview.chromium.org/2856423002
Cr-Commit-Position: refs/heads/master@{#472595}
19 files changed
