Disable accessibility hooks after test run
Accessibility hooks at WebTestProxy was still active after the test run. This caused WebNodes to be stored after test run in AccessibilityController, causing content_shell leak detector to report false positives on some LayoutTests.
This patch disables accessibility event hook at WebTestProxy if the testRunner is not running.
BUG=332630,364760
Review URL: https://codereview.chromium.org/
237963023
git-svn-id: svn://svn.chromium.org/chrome/trunk/src@264770 0039d316-1c4b-4281-b951-d872f2087c98