Reland of Delete class SSRCDatabase, and its global ssrc registry.

webrtc/modules/rtp_rtcp/source/rtp_rtcp_impl_unittest.cc

 /*
  *  Copyright (c) 2013 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.
  */
 
@@ skipping 150 matching lines @@
 };
 }  // namespace
 
 class RtpRtcpImplTest : public ::testing::Test {
  protected:
   RtpRtcpImplTest()
       : clock_(133590000000000),
         sender_(&clock_),
         receiver_(&clock_) {
     // Send module.
+    sender_.impl_->SetSSRC(kSenderSsrc);
     EXPECT_EQ(0, sender_.impl_->SetSendingStatus(true));
     sender_.impl_->SetSendingMediaStatus(true);
-    sender_.impl_->SetSSRC(kSenderSsrc);
     sender_.SetRemoteSsrc(kReceiverSsrc);
     sender_.impl_->SetSequenceNumber(kSequenceNumber);
     sender_.impl_->SetStorePacketsStatus(true, 100);
 
     memset(&codec_, 0, sizeof(VideoCodec));
     codec_.plType = 100;
     strncpy(codec_.plName, "VP8", 3);
     codec_.width = 320;
     codec_.height = 180;
     EXPECT_EQ(0, sender_.impl_->RegisterSendPayload(codec_));
@@ skipping 370 matching lines @@
   EXPECT_EQ(6U, receiver_.RtcpSent().unique_nack_requests);
   EXPECT_THAT(receiver_.LastNackListSent(), ElementsAre(11, 18, 20, 21));
 
   // Send module receives the request.
   EXPECT_EQ(2U, sender_.RtcpReceived().nack_packets);
   EXPECT_EQ(8U, sender_.RtcpReceived().nack_requests);
   EXPECT_EQ(6U, sender_.RtcpReceived().unique_nack_requests);
   EXPECT_EQ(75, sender_.RtcpReceived().UniqueNackRequestsInPercent());
 }
 }  // namespace webrtc