Generate intervention reports and route them to ReportingObserver.

This patch implements a centralized location for the generation of
intervention reports, which both sends a message to the console,
and routes the reports to any registered ReportingObservers.

This patch also connects the existing interventions in TouchEvent to
utilize this new flow. Other interventions will need to be connected in
future patches.

Bug: 564071, 731810
Change-Id: I0aa435ca6ebfe5950fbcd8795b678852a55f5d28
Reviewed-on: https://chromium-review.googlesource.com/652958
Commit-Queue: Paul Meyer <paulmeyer@chromium.org>
Reviewed-by: Nate Chapin <japhet@chromium.org>
Cr-Commit-Position: refs/heads/master@{#503363}
11 files changed