Revert of Enable a11y audit for chrome://settings

Revert of Enable a11y audit for chrome://settings (patchset #10 id:170001 of https://codereview.chromium.org/646853004/)

Reason for revert:
Causes (timeout) failures in OptionsWebUIExtendedTest.CloseOverlayNoHistory on Windows 7.

Trouble started with this build.
https://build.chromium.org/p/chromium.win/builders/Win7%20Tests%20%28dbg%29%281%29/builds/32871

---

OptionsWebUIExtendedTest.CloseOverlayNoHistory (run #1):
[ RUN      ] OptionsWebUIExtendedTest.CloseOverlayNoHistory

OptionsWebUIExtendedTest.CloseOverlayNoHistory (run #2):
[ RUN      ] OptionsWebUIExtendedTest.CloseOverlayNoHistory
[1616:2160:1120/144446:WARNING:data_reduction_proxy_settings.cc(319)] SPDY proxy OFF at startup
[4804:2920:1120/144449:ERROR:singleton_hwnd.cc(43)] Cannot create windows on non-UI thread!
[4224:4604:1120/144455:ERROR:singleton_hwnd.cc(43)] Cannot create windows on non-UI thread!
[1616:2160:1120/144459:INFO:CONSOLE(1283)] "Running TestCase OptionsWebUIExtendedTest.CloseOverlayNoHistory", source: test_api.js (1283)

OptionsWebUIExtendedTest.CloseOverlayNoHistory (run #3):
[ RUN      ] OptionsWebUIExtendedTest.CloseOverlayNoHistory
[3656:3020:1120/144549:WARNING:data_reduction_proxy_settings.cc(319)] SPDY proxy OFF at startup
[3552:4476:1120/144552:ERROR:singleton_hwnd.cc(43)] Cannot create windows on non-UI thread!
[3836:4860:1120/144558:ERROR:singleton_hwnd.cc(43)] Cannot create windows on non-UI thread!
[3656:3020:1120/144602:INFO:CONSOLE(1283)] "Running TestCase OptionsWebUIExtendedTest.CloseOverlayNoHistory", source: test_api.js (1283)

OptionsWebUIExtendedTest.CloseOverlayNoHistory (run #4):
[ RUN      ] OptionsWebUIExtendedTest.CloseOverlayNoHistory
[3408:4740:1120/144634:WARNING:data_reduction_proxy_settings.cc(319)] SPDY proxy OFF at startup
[3136:3924:1120/144637:ERROR:singleton_hwnd.cc(43)] Cannot create windows on non-UI thread!
[4424:4988:1120/144643:ERROR:singleton_hwnd.cc(43)] Cannot create windows on non-UI thread!
[3408:4740:1120/144647:INFO:CONSOLE(1283)] "Running TestCase OptionsWebUIExtendedTest.CloseOverlayNoHistory", source: test_api.js (1283)

Original issue's description:
> Enable a11y audit for chrome://settings
>
> Enabled the tests and fixed failure. Failure was due to transition obscuring elements in the UI.
>
> Another failure was caused because there were no labels on the mic and camera drop downs.
>
> Another failure was that there was no captions for a video element. This is used to capture a profile picture in chrome OS, so there wouldn't be any captions. This element is ignored in the a11y audit.
>
> There was also an issue with the dispatching of events in the ensureTransitionEndEvent function that wouldn't allow the event to bubble.
>
> BUG=311866
>
> Committed: https://crrev.com/34a84c6d1269332cc3ae2b8a50af489230c885de
> Cr-Commit-Position: refs/heads/master@{#301266}
>
> Committed: https://crrev.com/ca8b4ecfeee16828955ffe5637749272a5989106
> Cr-Commit-Position: refs/heads/master@{#305078}

TBR=dbeam@chromium.org,hcarmona@chromium.org
NOTREECHECKS=true
NOTRY=true
BUG=311866
Committed: https://crrev.com/766b8b1a67411d10b8b03251237643338685e831
Cr-Commit-Position: refs/heads/master@{#305112}

[Mark P, 2014-11-20 23:48:47]

Created Revert of Enable a11y audit for chrome://settings

[commit-bot: I haz the power, 2014-11-20 23:50:17]

CQ is trying da patch. Follow status at
 https://chromium-cq-status.appspot.com/patch-status/745953002/1

[commit-bot: I haz the power, 2014-11-20 23:52:20]

Committed patchset #1 (id:1)

[commit-bot: I haz the power, 2014-11-20 23:52:57]

Patchset 1 (id:??) landed as
https://crrev.com/766b8b1a67411d10b8b03251237643338685e831
Cr-Commit-Position: refs/heads/master@{#305112}