[rtp_rtcp] fixed namespaces lint warnings

webrtc/modules/rtp_rtcp/test/testAPI/test_api_rtcp.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 <algorithm>
 #include <vector>
 
 #include "testing/gmock/include/gmock/gmock.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "webrtc/common_types.h"
 #include "webrtc/modules/rtp_rtcp/include/receive_statistics.h"
 #include "webrtc/modules/rtp_rtcp/include/rtp_rtcp.h"
 #include "webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h"
 #include "webrtc/modules/rtp_rtcp/source/rtp_receiver_audio.h"
 #include "webrtc/modules/rtp_rtcp/test/testAPI/test_api.h"
 
-using namespace webrtc;
+namespace webrtc {
+namespace {
 
 const uint64_t kTestPictureId = 12345678;
 const uint8_t kSliPictureId = 156;
 
 class RtcpCallback : public RtcpIntraFrameObserver {
  public:
   void SetModule(RtpRtcp* module) {
     _rtpRtcpModule = module;
   };
   virtual void OnRTCPPacketTimeout(const int32_t id) {
@@ skipping 225 matching lines @@
 
   // |test_ssrc+1| is the SSRC of module2 that send the report.
   EXPECT_EQ(test_ssrc+1, report_blocks[0].remoteSSRC);
   EXPECT_EQ(test_ssrc, report_blocks[0].sourceSSRC);
 
   EXPECT_EQ(0u, report_blocks[0].cumulativeLost);
   EXPECT_LT(0u, report_blocks[0].delaySinceLastSR);
   EXPECT_EQ(test_sequence_number, report_blocks[0].extendedHighSeqNum);
   EXPECT_EQ(0u, report_blocks[0].fractionLost);
 }
+
+}  // namespace
+}  // namespace webrtc