Re-focus node with Android accessibility focus when it moves

Re-focus node with Android accessibility focus when it moves

This is a workaround for an Android accessibility bug - when the object with accessibility focus moves, Android doesn't update the bounds of accessibility focus on the screen, even if we send a WINDOW_CONTENT_CHANGED event.

With this change, we keep track of the bounding rect of the node with accessibility focus, and if it changes, we move focus to the document and then back to this node, which works around the issue.

No visual flicker was observed when testing on multiple devices. Refreshable braille displays flicker briefly.

BUG=407871
Committed: https://crrev.com/9e8fa203c7856353cf342f9394298e4e49735dcc
Cr-Commit-Position: refs/heads/master@{#292402}

[dmazzoni, 2014-08-26 23:12:09]

dmazzoni@chromium.org changed reviewers:
+ plundblad@chromium.org

[Peter Lundblad, 2014-08-27 09:52:56]

lgtm

https://codereview.chromium.org/505423002/diff/20001/content/public/android/j...
File
content/public/android/java/src/org/chromium/content/browser/accessibility/BrowserAccessibilityManager.java
(right):

https://codereview.chromium.org/505423002/diff/20001/content/public/android/j...
content/public/android/java/src/org/chromium/content/browser/accessibility/BrowserAccessibilityManager.java:575:
moveAccessibilityFocusToIdAndRefocusIfNeeded(virtualViewId);
Does it work to send a clear a11y focus event instead of focusing the
document?  Focusing a node emits feedback and depending on device load etc.
this might be audible/detectable by the user. In my experience, clearing
doesn't have that issue.

[dmazzoni, 2014-08-27 19:29:46]

On 2014/08/27 09:52:56, Peter Lundblad wrote:
> lgtm
> 
>
https://codereview.chromium.org/505423002/diff/20001/content/public/android/j...
> File
>
content/public/android/java/src/org/chromium/content/browser/accessibility/BrowserAccessibilityManager.java
> (right):
> 
>
https://codereview.chromium.org/505423002/diff/20001/content/public/android/j...
>
content/public/android/java/src/org/chromium/content/browser/accessibility/BrowserAccessibilityManager.java:575:
> moveAccessibilityFocusToIdAndRefocusIfNeeded(virtualViewId);
> Does it work to send a clear a11y focus event instead of focusing the
> document?  Focusing a node emits feedback and depending on device load etc.
> this might be audible/detectable by the user. In my experience, clearing
> doesn't have that issue.

Yep, that works - thanks. I made the change in the parent changelist:
https://codereview.chromium.org/513483002/

[dmazzoni, 2014-08-27 19:30:02]

The CQ bit was checked by dmazzoni@chromium.org

[dmazzoni, 2014-08-27 19:30:13]

The CQ bit was unchecked by dmazzoni@chromium.org

[dmazzoni, 2014-08-28 15:58:47]

The CQ bit was checked by dmazzoni@chromium.org

[commit-bot: I haz the power, 2014-08-28 15:59:52]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/dmazzoni@chromium.org/505423002/40001

[commit-bot: I haz the power, 2014-08-28 16:54:31]

Committed patchset #3 (id:40001) as 86a4fd65c614a4bc635a205a661d95a948d26267

[commit-bot: I haz the power, 2014-09-10 03:00:12]

Patchset 3 (id:??) landed as
https://crrev.com/9e8fa203c7856353cf342f9394298e4e49735dcc
Cr-Commit-Position: refs/heads/master@{#292402}