Fix crash in WorkerTest.MultipleTabsQueuedSharedWorker. I could get this...

Fix crash in WorkerTest.MultipleTabsQueuedSharedWorker. I could get this consistently when running debug content_browsertests builds in VS.

BUG=69881
Review URL: https://chromiumcodereview.appspot.com/10828033

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@148584 0039d316-1c4b-4281-b951-d872f2087c98

content/browser/worker_host/worker_service_impl.cc

@@ -62,6 +62,17 @@ void WorkerServiceImpl::OnWorkerMessageFilterClosing(
     }
   }
 
+  for (WorkerProcessHost::Instances::iterator i =
+           pending_shared_workers_.begin();
+       i != pending_shared_workers_.end(); ) {
+     i->RemoveFilters(filter);
+     if (i->NumFilters() == 0) {
+      i = pending_shared_workers_.erase(i);
+    } else {
+      ++i;
+    }
+  }
+
   // Also, see if that process had any pending shared workers.
   for (WorkerProcessHost::Instances::iterator iter =
            pending_shared_workers_.begin();