Code:  void HistoryModelWorker::DoWorkAndWaitUntilDone(Callback0::Type* work) {
   WaitableEvent done(false, false);
   scoped_refptr<WorkerTask> task(new WorkerTask(work, &done));
  history_service_->ScheduleDBTask(task.get(), this);
   done.Wait();
 }

Vulnerability Type: DoS 
CWE ID: CWE-399
Summary: Use-after-free vulnerability in Google Chrome before 12.0.742.112 allows remote attackers to cause a denial of service or possibly have unspecified other impact via vectors involving SVG use elements.
Commit Message: Enable HistoryModelWorker by default, now that bug 69561 is fixed.

BUG=69561
TEST=Run sync manually and run integration tests, sync should not crash.

Review URL: http://codereview.chromium.org/7016007

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@85211 0039d316-1c4b-4281-b951-d872f2087c98