Fix flakiness in AccessibilityFeaturesApiTest.Set tests

Fix flakiness in AccessibilityFeaturesApiTest.Set tests

The problem with tests was that spoken feedback was getting enabled just
before loading the test extension. This would cause two extensions being
loaded: ChromeVox extension (which gets loaded when spoken feedback is
enabled) and the test extension. This is situation extension API tests
don't handle well. They wait for the test extension to get loaded by
waiting for any EXTENSION_LOADED notification. If the ChromeVox extension
got loaded before the test extension, the extension api test would continue
running too soon (before the test extension was loaded), and fail when the
test extension could not be found in extension set by its path.

To avoid that, keep spoken feedback disabled at the start of the test
(which should ensure that the ChromeVox extension doesn't get loaded while
the test extension is loading).

BUG=384266
Committed: https://src.chromium.org/viewvc/chrome?view=rev&revision=278269

[Peter Lundblad, 2014-06-18 02:37:03]

lgtm

https://codereview.chromium.org/331383002/diff/1/chrome/browser/chromeos/exte...
File chrome/browser/chromeos/extensions/accessibility_features_apitest.cc
(right):

https://codereview.chromium.org/331383002/diff/1/chrome/browser/chromeos/exte...
chrome/browser/chromeos/extensions/accessibility_features_apitest.cc:263: <<
message_;
nit: would this line fit on the previous one?

[tbarzic, 2014-06-18 03:07:36]

https://codereview.chromium.org/331383002/diff/1/chrome/browser/chromeos/exte...
File chrome/browser/chromeos/extensions/accessibility_features_apitest.cc
(right):

https://codereview.chromium.org/331383002/diff/1/chrome/browser/chromeos/exte...
chrome/browser/chromeos/extensions/accessibility_features_apitest.cc:263: <<
message_;
On 2014/06/18 02:37:03, Peter Lundblad wrote:
> nit: would this line fit on the previous one?

It probably would, but I find it more readable this way.

[asargent_no_longer_on_chrome, 2014-06-19 00:17:56]

lgtm

[tbarzic, 2014-06-19 00:18:40]

The CQ bit was checked by tbarzic@chromium.org

[commit-bot: I haz the power, 2014-06-19 00:19:54]

CQ is trying da patch. Follow status at
 https://chromium-status.appspot.com/cq/tbarzic@chromium.org/331383002/1

[commit-bot: I haz the power, 2014-06-19 04:20:52]

Change committed as 278269