GitLab

Added new SingleSharedWorker and MultipleSharedWorker tests, and enabled a bunch of other tests after marking them flaky/excluding them from valgrind.

Review URL: http://codereview.chromium.org/490023

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@34429 0039d316-1c4b-4281-b951-d872f2087c98