Detect situation when there is no missing send completion signal in P2PSocket implementation.

content/renderer/p2p/socket_client_impl.cc

Index: content/renderer/p2p/socket_client_impl.cc
diff --git a/content/renderer/p2p/socket_client_impl.cc b/content/renderer/p2p/socket_client_impl.cc
index 1425151089cf42930e66dfd190dff516af893b44..55e75293642ddd558036ec418f25bc7a482d179d 100644
--- a/content/renderer/p2p/socket_client_impl.cc
+++ b/content/renderer/p2p/socket_client_impl.cc
@@ -69,25 +69,35 @@ void P2PSocketClientImpl::DoInit(P2PSocketType type,
       type, socket_id_, local_address, remote_address));
 }
 
-void P2PSocketClientImpl::SendWithDscp(
-    const net::IPEndPoint& address,
-    const std::vector<char>& data,
-    const rtc::PacketOptions& options) {
+uint64 P2PSocketClientImpl::SendWithDscp(const net::IPEndPoint& address,
+                                         const std::vector<char>& data,
+                                         const rtc::PacketOptions& options) {
+  uint64 unique_id = GetUniqueId(random_socket_id_, ++next_packet_id_);
   if (!ipc_message_loop_->BelongsToCurrentThread()) {
     ipc_message_loop_->PostTask(
-        FROM_HERE, base::Bind(
-            &P2PSocketClientImpl::SendWithDscp, this, address, data, options));
-    return;
+        FROM_HERE, base::Bind(&P2PSocketClientImpl::SendWithDscpAndPacketId,
+                              this, address, data, options, unique_id));
+    return unique_id;
   }
 
   // Can send data only when the socket is open.
   DCHECK(state_ == STATE_OPEN || state_ == STATE_ERROR);
   if (state_ == STATE_OPEN) {
-    uint64 unique_id = GetUniqueId(random_socket_id_, ++next_packet_id_);
-    TRACE_EVENT_ASYNC_BEGIN0("p2p", "Send", unique_id);
-    dispatcher_->SendP2PMessage(new P2PHostMsg_Send(socket_id_, address, data,
-                                                    options, unique_id));
+    SendWithDscpAndPacketId(address, data, options, unique_id);
   }
+
+  return unique_id;
+}
+
+void P2PSocketClientImpl::SendWithDscpAndPacketId(
+    const net::IPEndPoint& address,
+    const std::vector<char>& data,
+    const rtc::PacketOptions& options,
+    uint64 packet_id) {
+  DCHECK_EQ(state_, STATE_OPEN);
+  TRACE_EVENT_ASYNC_BEGIN0("p2p", "Send", packet_id);
+  dispatcher_->SendP2PMessage(
+      new P2PHostMsg_Send(socket_id_, address, data, options, packet_id));
 }
 
 void P2PSocketClientImpl::Send(const net::IPEndPoint& address,
@@ -196,17 +206,20 @@ void P2PSocketClientImpl::DeliverOnIncomingTcpConnection(
   }
 }
 
-void P2PSocketClientImpl::OnSendComplete() {
+void P2PSocketClientImpl::OnSendComplete(
+    const P2PSendPacketMetrics& send_metrics) {
   DCHECK(ipc_message_loop_->BelongsToCurrentThread());
 
   delegate_message_loop_->PostTask(
-      FROM_HERE, base::Bind(&P2PSocketClientImpl::DeliverOnSendComplete, this));
+      FROM_HERE, base::Bind(&P2PSocketClientImpl::DeliverOnSendComplete, this,
+                            send_metrics));
 }
 
-void P2PSocketClientImpl::DeliverOnSendComplete() {
+void P2PSocketClientImpl::DeliverOnSendComplete(
+    const P2PSendPacketMetrics& send_metrics) {
   DCHECK(delegate_message_loop_->BelongsToCurrentThread());
   if (delegate_)
-    delegate_->OnSendComplete();
+    delegate_->OnSendComplete(send_metrics);
 }
 
 void P2PSocketClientImpl::OnError() {