Remove use of stl_util's STLDeleteContainerPairSecondPointers from content/.

content/browser/renderer_host/p2p/socket_host_udp.cc

Index: content/browser/renderer_host/p2p/socket_host_udp.cc
diff --git a/content/browser/renderer_host/p2p/socket_host_udp.cc b/content/browser/renderer_host/p2p/socket_host_udp.cc
index 2eb3579b99800addbe0f85a0f310ae708d1b85cc..70ab3af55b716e62a0a1c351c9fbf548de3e6a09 100644
--- a/content/browser/renderer_host/p2p/socket_host_udp.cc
+++ b/content/browser/renderer_host/p2p/socket_host_udp.cc
@@ -401,8 +401,9 @@ void P2PSocketHostUdp::HandleSendResult(uint64_t packet_id,
       P2PSendPacketMetrics(packet_id, transport_sequence_number, send_time)));
 }
 
-P2PSocketHost* P2PSocketHostUdp::AcceptIncomingTcpConnection(
-    const net::IPEndPoint& remote_address, int id) {
+std::unique_ptr<P2PSocketHost> P2PSocketHostUdp::AcceptIncomingTcpConnection(
+    const net::IPEndPoint& remote_address,
+    int id) {
   NOTREACHED();
   OnError();
   return NULL;