The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/9cd13b2cd1f50c5660b434c40070363e28ece434

commit 9cd13b2cd1f50c5660b434c40070363e28ece434
Author: dmazzoni <dmazzoni@chromium.org>
Date: Sun May 01 00:07:59 2016

Add verbose logging for native accessibility events.

Introduce a new class BrowserAccessibilityEvent and
use it to encapsulate more information about
native accessibility events, and optionally log
information about events sent and also those that
are discarded (and why). This will make it easier to
debug problems with accessibility events in the future.

BUG= 607703 

Review-Url: https://codereview.chromium.org/1925473002
Cr-Commit-Position: refs/heads/master@{#390867}

[modify] https://crrev.com/9cd13b2cd1f50c5660b434c40070363e28ece434/content/browser/accessibility/browser_accessibility.cc
[modify] https://crrev.com/9cd13b2cd1f50c5660b434c40070363e28ece434/content/browser/accessibility/browser_accessibility_android.cc
[add] https://crrev.com/9cd13b2cd1f50c5660b434c40070363e28ece434/content/browser/accessibility/browser_accessibility_event.cc
[add] https://crrev.com/9cd13b2cd1f50c5660b434c40070363e28ece434/content/browser/accessibility/browser_accessibility_event.h
[add] https://crrev.com/9cd13b2cd1f50c5660b434c40070363e28ece434/content/browser/accessibility/browser_accessibility_event_win.cc
[add] https://crrev.com/9cd13b2cd1f50c5660b434c40070363e28ece434/content/browser/accessibility/browser_accessibility_event_win.h
[modify] https://crrev.com/9cd13b2cd1f50c5660b434c40070363e28ece434/content/browser/accessibility/browser_accessibility_manager.cc
[modify] https://crrev.com/9cd13b2cd1f50c5660b434c40070363e28ece434/content/browser/accessibility/browser_accessibility_manager.h
[modify] https://crrev.com/9cd13b2cd1f50c5660b434c40070363e28ece434/content/browser/accessibility/browser_accessibility_manager_android.cc
[modify] https://crrev.com/9cd13b2cd1f50c5660b434c40070363e28ece434/content/browser/accessibility/browser_accessibility_manager_android.h
[modify] https://crrev.com/9cd13b2cd1f50c5660b434c40070363e28ece434/content/browser/accessibility/browser_accessibility_manager_auralinux.cc
[modify] https://crrev.com/9cd13b2cd1f50c5660b434c40070363e28ece434/content/browser/accessibility/browser_accessibility_manager_auralinux.h
[modify] https://crrev.com/9cd13b2cd1f50c5660b434c40070363e28ece434/content/browser/accessibility/browser_accessibility_manager_mac.h
[modify] https://crrev.com/9cd13b2cd1f50c5660b434c40070363e28ece434/content/browser/accessibility/browser_accessibility_manager_mac.mm
[modify] https://crrev.com/9cd13b2cd1f50c5660b434c40070363e28ece434/content/browser/accessibility/browser_accessibility_manager_win.cc
[modify] https://crrev.com/9cd13b2cd1f50c5660b434c40070363e28ece434/content/browser/accessibility/browser_accessibility_manager_win.h
[modify] https://crrev.com/9cd13b2cd1f50c5660b434c40070363e28ece434/content/browser/accessibility/browser_accessibility_win.cc
[modify] https://crrev.com/9cd13b2cd1f50c5660b434c40070363e28ece434/content/browser/accessibility/browser_accessibility_win.h
[modify] https://crrev.com/9cd13b2cd1f50c5660b434c40070363e28ece434/content/content_browser.gypi