GitLab

In
https://chromium-review.googlesource.com/c/chromium/src/+/2261098

TtsUtteranceImpl started taking an optional WebContents in its
constructor.

When the WebContents is destroyed, the utterance is cleared and stopped
from triggering tts.

This change exposes this behavior up to c/p/b and cleans up
AccessibilityManager which approximated this behavior by calling
TtsController::Stop().

Some notable examples that benefit from this:
- extensions that trigger tts utterances, when destroyed, stop those
  utterances
- the tts settings webui, if closed, will stop tts utterances in
  progress

Change-Id: I7169b7ea3093e24e093c6c478040d943f34353f5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2541002
Commit-Queue: David Tseng <dtseng@chromium.org>
Reviewed-by: Avi Drissman <avi@chromium.org>
Cr-Commit-Position: refs/heads/master@{#828529}