Revert 272998 "Revert 241291 "Fix a long standing leak on cancel..."

trunk/src/content/child/resource_dispatcher.cc

Index: trunk/src/content/child/resource_dispatcher.cc
===================================================================
--- trunk/src/content/child/resource_dispatcher.cc	(revision 272999)
+++ trunk/src/content/child/resource_dispatcher.cc	(working copy)
@@ -588,11 +588,8 @@
     return;
   }
 
-  SiteIsolationPolicy::OnRequestComplete(request_id);
-  PendingRequestInfo& request_info = it->second;
-  ReleaseResourcesInMessageQueue(&request_info.deferred_message_queue);
-  pending_requests_.erase(it);
-
+  // |request_id| will be removed from |pending_requests_| when
+  // OnRequestComplete returns with ERR_ABORTED.
   message_sender()->Send(new ResourceHostMsg_CancelRequest(request_id));
 }