Initialize PeerConnection members in declaration order and destroy them in reverse order.

webrtc/pc/peerconnection.h

Index: webrtc/pc/peerconnection.h
diff --git a/webrtc/pc/peerconnection.h b/webrtc/pc/peerconnection.h
index 23e7e8e58b083b035872dd137efeeb4f2e82bf92..1e2ca3bb95487baa5d519967c3237314c0726c6c 100644
--- a/webrtc/pc/peerconnection.h
+++ b/webrtc/pc/peerconnection.h
@@ -402,14 +402,16 @@ class PeerConnection : public PeerConnectionInterface,
   rtc::scoped_refptr<PeerConnectionFactory> factory_;
   PeerConnectionObserver* observer_;
   UMAObserver* uma_observer_;
+
+  // The EventLog needs to outlive |call_| (and any other object that uses it).
+  std::unique_ptr<RtcEventLog> event_log_;
+
   SignalingState signaling_state_;
   IceConnectionState ice_connection_state_;
   IceGatheringState ice_gathering_state_;
   PeerConnectionInterface::RTCConfiguration configuration_;
 
   std::unique_ptr<cricket::PortAllocator> port_allocator_;
-  // The EventLog needs to outlive |call_|.
-  std::unique_ptr<RtcEventLog> event_log_;
 
   // One PeerConnection has only one RTCP CNAME.
   // https://tools.ietf.org/html/draft-ietf-rtcweb-rtp-usage-26#section-4.9
@@ -436,15 +438,16 @@ class PeerConnection : public PeerConnectionInterface,
 
   bool remote_peer_supports_msid_ = false;
 
+  std::unique_ptr<Call> call_;
+  std::unique_ptr<WebRtcSession> session_;
+  std::unique_ptr<StatsCollector> stats_;  // A pointer is passed to senders_
+  rtc::scoped_refptr<RTCStatsCollector> stats_collector_;
+
   std::vector<rtc::scoped_refptr<RtpSenderProxyWithInternal<RtpSenderInternal>>>
       senders_;
   std::vector<
       rtc::scoped_refptr<RtpReceiverProxyWithInternal<RtpReceiverInternal>>>
       receivers_;
-  std::unique_ptr<WebRtcSession> session_;
-  std::unique_ptr<Call> call_;
-  std::unique_ptr<StatsCollector> stats_;
-  rtc::scoped_refptr<RTCStatsCollector> stats_collector_;
 };
 
 }  // namespace webrtc