Also need to stop speech on disable.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/6264a8e359685b6c4689addfabf7e74585fbb105

commit 6264a8e359685b6c4689addfabf7e74585fbb105
Author: Katie D <katie@chromium.org>
Date: Wed Feb 07 02:32:20 2018

Turn off focus ring highlight and tts when STS is disabled.

Also turns of tts when chromevox is disabled.

Bug:  809733 
Change-Id: I9a9c6b6b2c314f29b3207f1ed38b0820d878c430
Reviewed-on: https://chromium-review.googlesource.com/905807
Reviewed-by: David Tseng <dtseng@chromium.org>
Commit-Queue: Katie Dektar <katie@chromium.org>
Cr-Commit-Position: refs/heads/master@{#534886}
[modify] https://crrev.com/6264a8e359685b6c4689addfabf7e74585fbb105/chrome/browser/chromeos/accessibility/accessibility_manager.cc
[modify] https://crrev.com/6264a8e359685b6c4689addfabf7e74585fbb105/chrome/browser/chromeos/accessibility/accessibility_manager.h

Google Chrome 67.0.3369.0 (Official Build) canary (64-bit)
Firmware Version Google_Samus.6300.276.0
Flag enabled: #enable-experimental-accessibility-features

# Enable STS in Status bar > Accessibility 
# Use search + drag highlight to start STS speaking and highlighting on Status bar > Accessibility 
# While it's reading, click Select To Speak to turn off feature

Works as expected, it turns off and highlight ring is gone. 

Moving from just having STS label to also having the UI>Accessibility>SelectToSpeak component to make searching easier in the future.