In RtpPacket do not keep pointer to RtpHeaderExtensionMap

webrtc/modules/rtp_rtcp/source/rtp_packet_unittest.cc

 /*
  *  Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
  *
  *  Use of this source code is governed by a BSD-style license
  *  that can be found in the LICENSE file in the root of the source
  *  tree. An additional intellectual property rights grant can be found
  *  in the file PATENTS.  All contributing project authors may
  *  be found in the AUTHORS file in the root of the source tree.
  */
 #include "webrtc/modules/rtp_rtcp/source/rtp_packet_received.h"
@@ skipping 275 matching lines @@
   EXPECT_EQ(kSeqNum, packet.SequenceNumber());
   EXPECT_EQ(kTimestamp, packet.Timestamp());
   EXPECT_EQ(kSsrc, packet.Ssrc());
 
   RtpPacketToSend::ExtensionManager extensions;
   extensions.Register(kRtpExtensionTransmissionTimeOffset,
                       kTransmissionOffsetExtensionId);
 
   int32_t time_offset;
   EXPECT_FALSE(packet.GetExtension<TransmissionOffset>(&time_offset));
-  packet.IdentifyExtensions(&extensions);
+  packet.IdentifyExtensions(extensions);
   EXPECT_TRUE(packet.GetExtension<TransmissionOffset>(&time_offset));
   EXPECT_EQ(kTimeOffset, time_offset);
   EXPECT_EQ(0u, packet.payload_size());
   EXPECT_EQ(0u, packet.padding_size());
 }
 
 }  // namespace webrtc