Reland #2: Ensure WebView notifies desktop automation on creation, destruction, and change Original

Reland #2: Ensure WebView notifies desktop automation on creation, destruction, and change

Original issue: https://codereview.chromium.org/880063002
Previous reland attempt: https://codereview.chromium.org/895623003/

This cl changes the way in which ChromeVox initially verbalizes a page which led to flakeyness in
  chromevox_tests --gtest_filter=BackgroundTest.*

To attempt and address the flakeyness,
- chromevox_e2e_test_base.js and chromevox_next_e2e_test_base.js now explicitly separates listening to page load events from the chrome.automation tree and the chrome.tabs APIs.
They are named: runWithLoadedTree, runWithLoadedTab, and runWithTab. The last method allows a caller to create a tab, but not wait for it to load (based on the tab status being 'complete').
- each test in background_test now no longer waits for ChromeVox to speak 'start' (which formerly could have been triggered by a loadComplete automation event).
- tab creation is still done via the tabs API, but listening for load is done via chrome.automation. (i.e. add a listener for an automation tree to load completely, then create a tab).

It is not known at this time if this cl will continue to cause flakes in the above tests. Try bots and local runs yielded no flakeyness. The next step may be to introduce logging to identify the source of the flakeyness.

TBR=tfarina

Committed: https://crrev.com/9b006b56ca402da3774708f08e062c89018d57a6
Cr-Commit-Position: refs/heads/master@{#315362}

[David Tseng, 2015-02-05 00:08:53]

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

[David Tseng, 2015-02-05 00:22:25]

dtseng@chromium.org changed reviewers:
+ tfarina@chromium.org

[David Tseng, 2015-02-05 03:20:54]

Ok; I cleaned up the test code in this cl a little. Mostly, I removed mixing
tabs and automation as sources for waiting on doc load.

As before, I don't see any flakeyness locally or on try bots. This might be a
case where I might request to land and add additional logging to try and resolve
the issue. Other suggestions welcome.

[dmazzoni, 2015-02-05 16:36:16]

lgtm

[tfarina, 2015-02-05 16:41:28]

Could you state in the CL description why it was reverted last time (and perhaps
what you did to mitigate it) and pinpoint your fix for it in the diff?

[David Tseng, 2015-02-05 18:59:01]

New patchsets have been uploaded after l-g-t-m from dmazzoni@chromium.org

[David Tseng, 2015-02-05 18:59:41]

On 2015/02/05 16:41:28, tfarina wrote:
> Could you state in the CL description why it was reverted last time (and
perhaps
> what you did to mitigate it) and pinpoint your fix for it in the diff?

Done.

[David Tseng, 2015-02-06 18:48:06]

tfarina, just wanted to ensure you're ok with this change now. Would like to
land this morning so I can monitor any flakes throughout the day.

On 2015/02/05 18:59:41, David Tseng wrote:
> On 2015/02/05 16:41:28, tfarina wrote:
> > Could you state in the CL description why it was reverted last time (and
> perhaps
> > what you did to mitigate it) and pinpoint your fix for it in the diff?
> 
> Done.

[tfarina, 2015-02-07 00:39:38]

I haven't reviewed it. I trust Dominic's review. If he is fine then go ahead.

[David Tseng, 2015-02-09 19:04:36]

The CQ bit was checked by dtseng@chromium.org

[commit-bot: I haz the power, 2015-02-09 19:05:17]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/890013006/120001

[commit-bot: I haz the power, 2015-02-09 19:11:51]

The CQ bit was unchecked by commit-bot@chromium.org

[commit-bot: I haz the power, 2015-02-09 19:11:52]

Try jobs failed on following builders:
  chromium_presubmit on tryserver.chromium.linux (JOB_FAILED,
http://build.chromium.org/p/tryserver.chromium.linux/builders/chromium_presub...)

[David Tseng, 2015-02-09 19:18:55]

The CQ bit was checked by dtseng@chromium.org

[commit-bot: I haz the power, 2015-02-09 19:20:35]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/890013006/120001

[commit-bot: I haz the power, 2015-02-09 19:24:37]

Committed patchset #7 (id:120001)

[commit-bot: I haz the power, 2015-02-09 19:25:21]

Patchset 7 (id:??) landed as
https://crrev.com/9b006b56ca402da3774708f08e062c89018d57a6
Cr-Commit-Position: refs/heads/master@{#315362}

[jiayl, 2015-02-09 20:16:54]

A revert of this CL (patchset #7 id:120001) has been created in
https://codereview.chromium.org/910013002/ by jiayl@chromium.org.

The reason for reverting is: Suspected to cause chromeos vox test failure:
http://build.chromium.org/p/chromium.chromiumos/builders/Linux%20ChromiumOS%2....

[David Tseng, 2015-02-09 21:22:14]

A revert of this CL (patchset #7 id:120001) has been created in
https://codereview.chromium.org/908853004/ by dtseng@chromium.org.

The reason for reverting is: Cause of flakes in chromevox_tests
BackgroundTest.*.