Suppress races in CallbackWasCalled (issue 313726)

TBR=pasko@chromium.org
BUG=313726

Review URL: https://codereview.chromium.org/68413011

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@234789 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 234789
Add chrome.autotestPrivate.getExtensionsInfo for security_BundledExtensions.

Code is based on TestingAutomationProvider::GetExtensionsInfo()
https://code.google.com/p/chromium/codesearch#chromium/src/chrome/browser/automation/testing_automation_provider.cc&l=3518-3584

BUG=220759
TEST=browser test, and manual testing

Review URL: https://codereview.chromium.org/70823002

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@234790 0039d316-1c4b-4281-b951-d872f2087c98
SVN changes up to revision 234790