Fix bug where DeterministicDispatcher CHECKed for killed jobs

headless/public/util/deterministic_dispatcher.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef HEADLESS_PUBLIC_UTIL_DETERMINISTIC_DISPATCHER_H_
 #define HEADLESS_PUBLIC_UTIL_DETERMINISTIC_DISPATCHER_H_
 
 #include <deque>
 #include <map>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
 #include "base/single_thread_task_runner.h"
 #include "base/synchronization/lock.h"
 #include "headless/public/util/url_request_dispatcher.h"
 #include "net/base/net_errors.h"
 
 namespace headless {
 
 class ManagedDispatchURLRequestJob;
 
 // The purpose of this class is to queue up calls to OnHeadersComplete and
@@ skipping 24 matching lines @@
 
   std::deque<ManagedDispatchURLRequestJob*> pending_requests_;
 
   using StatusMap = std::map<ManagedDispatchURLRequestJob*, net::Error>;
   StatusMap ready_status_map_;
 
   // Whether or not a MaybeDispatchJobOnIoThreadTask has been posted on the
   // |io_thread_task_runner_|
   bool dispatch_pending_;
 
+  base::WeakPtrFactory<DeterministicDispatcher> weak_ptr_factory_;
+
   DISALLOW_COPY_AND_ASSIGN(DeterministicDispatcher);
 };
 
 }  // namespace headless
 
 #endif  // HEADLESS_PUBLIC_UTIL_DETERMINISTIC_DISPATCHER_H_