GitLab

Move the rewriter files to ash, keep the delegate impl in chrome.
Add a mojo interface for the delegate to receive and return events.
Ash's controller creates the rewriter, Chrome sets the delegate.

Move, expand, and refine the existing unit tests.

Add TODOs to refine the rewriter/delegate/ChromeVox pattern.
(the rewriter shouldn't pass events that will need to be reposted)

This should allow Mash to support this rewriter in the future.
(for now, Ash doesn't get Window Service events sent to Chrome)

Bug: 647781
Test: No regressions with ChromeVox spoken feedback on Chrome OS.
Change-Id: I4f7805298156ab9463ca3110a1e957f922c6d82b
Reviewed-on: https://chromium-review.googlesource.com/1038819
Commit-Queue: Michael Wasserman <msw@chromium.org>
Reviewed-by: Tom Sepez <tsepez@chromium.org>
Reviewed-by: James Cook <jamescook@chromium.org>
Reviewed-by: David Tseng <dtseng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#555867}