Fix leak of RTCPeerConnectionHandler if PeerConnection.close() is called from js.

content/renderer/media/rtc_peer_connection_handler.h

 // Copyright (c) 2012 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 CONTENT_RENDERER_MEDIA_RTC_PEER_CONNECTION_HANDLER_H_
 #define CONTENT_RENDERER_MEDIA_RTC_PEER_CONNECTION_HANDLER_H_
 
 #include <map>
 #include <string>
 
@@ skipping 207 matching lines @@
       const FirstSessionDescription& remote);
 
   // Virtual to allow mocks to override.
   virtual scoped_refptr<base::SingleThreadTaskRunner> signaling_thread() const;
 
   void RunSynchronousClosureOnSignalingThread(const base::Closure& closure,
                                               const char* trace_event_name);
 
   base::ThreadChecker thread_checker_;
 
-  // |client_| is a weak pointer, and is valid until stop() has returned.
-  blink::WebRTCPeerConnectionHandlerClient* client_;
+  // |client_| is a weak pointer to the blink object (blink::RTCPeerConnection)
+  // that owns this object.
+  // It is valid for the lifetime of this object.
+  blink::WebRTCPeerConnectionHandlerClient* const client_;
+  // True if this PeerConnection has been closed.
+  // After the PeerConnection has been closed, this object may no longer
+  // forward callbacks to blink.
+  bool is_closed_;
 
   // |dependency_factory_| is a raw pointer, and is valid for the lifetime of
   // RenderThreadImpl.
   PeerConnectionDependencyFactory* const dependency_factory_;
 
   blink::WebFrame* frame_ = nullptr;
 
   ScopedVector<WebRtcMediaStreamAdapter> local_streams_;
 
   base::WeakPtr<PeerConnectionTracker> peer_connection_tracker_;
@@ skipping 31 matching lines @@
   bool ice_state_seen_[webrtc::PeerConnectionInterface::kIceConnectionMax] = {};
 
   base::WeakPtrFactory<RTCPeerConnectionHandler> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(RTCPeerConnectionHandler);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_RENDERER_MEDIA_RTC_PEER_CONNECTION_HANDLER_H_