[rtp_rtcp] fixed namespaces lint warnings

webrtc/modules/rtp_rtcp/source/rtcp_receiver_help.cc

 /*
  *  Copyright (c) 2012 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/rtcp_receiver_help.h"
 
 #include <assert.h>  // assert
 #include <string.h>  // memset
 
 #include "webrtc/modules/rtp_rtcp/source/rtcp_packet/transport_feedback.h"
 #include "webrtc/modules/rtp_rtcp/source/rtp_utility.h"
 
 namespace webrtc {
-using namespace RTCPHelp;
+namespace RTCPHelp {
 
 RTCPPacketInformation::RTCPPacketInformation()
     : rtcpPacketTypeFlags(0),
       remoteSSRC(0),
       nackSequenceNumbers(),
       applicationSubType(0),
       applicationName(0),
       applicationData(),
       applicationLength(0),
       rtt(0),
@@ skipping 152 matching lines @@
                          TmmbrSet.Tmmbr(sourceIdx),
                          TmmbrSet.PacketOH(sourceIdx),
                          TmmbrSet.Ssrc(sourceIdx));
   return 0;
 }
 
 void RTCPReceiveInformation::VerifyAndAllocateBoundingSet(
     const uint32_t minimumSize) {
   TmmbnBoundingSet.VerifyAndAllocateSet(minimumSize);
 }
+}  // namespace RTCPHelp
 }  // namespace webrtc