Close all active PeerConnections upon OS suspend (relanding r290125 and r291213)

content/renderer/media/peer_connection_tracker.cc

Index: content/renderer/media/peer_connection_tracker.cc
diff --git a/content/renderer/media/peer_connection_tracker.cc b/content/renderer/media/peer_connection_tracker.cc
index c4f10e5e88434578a57b989c5ddc17d8e48b7f73..8e368b4e564cf9283cb6792af8fb30b6f5a75d03 100644
--- a/content/renderer/media/peer_connection_tracker.cc
+++ b/content/renderer/media/peer_connection_tracker.cc
@@ -279,6 +279,7 @@ bool PeerConnectionTracker::OnControlMessageReceived(
   bool handled = true;
   IPC_BEGIN_MESSAGE_MAP(PeerConnectionTracker, message)
     IPC_MESSAGE_HANDLER(PeerConnectionTracker_GetAllStats, OnGetAllStats)
+    IPC_MESSAGE_HANDLER(PeerConnectionTracker_OnSuspend, OnSuspend)
     IPC_MESSAGE_UNHANDLED(handled = false)
   IPC_END_MESSAGE_MAP()
   return handled;
@@ -298,6 +299,13 @@ void PeerConnectionTracker::OnGetAllStats() {
   }
 }
 
+void PeerConnectionTracker::OnSuspend() {
+  for (PeerConnectionIdMap::iterator it = peer_connection_id_map_.begin();
+       it != peer_connection_id_map_.end(); ++it) {
+    it->first->CloseClientPeerConnection();
+  }
+}
+
 void PeerConnectionTracker::RegisterPeerConnection(
     RTCPeerConnectionHandler* pc_handler,
     const webrtc::PeerConnectionInterface::RTCConfiguration& config,