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

webrtc/voice_engine/channel_manager.h

 /*
  *  Copyright (c) 2011 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.
  */
 
 #ifndef WEBRTC_VOICE_ENGINE_CHANNEL_MANAGER_H
 #define WEBRTC_VOICE_ENGINE_CHANNEL_MANAGER_H
 
 #include <memory>
 #include <vector>
 
 #include "webrtc/base/constructormagic.h"
 #include "webrtc/base/criticalsection.h"
-#include "webrtc/base/random.h"
 #include "webrtc/base/scoped_ref_ptr.h"
 #include "webrtc/system_wrappers/include/atomic32.h"
 #include "webrtc/typedefs.h"
 #include "webrtc/voice_engine/include/voe_base.h"
 
 namespace webrtc {
 
 class AudioDecoderFactory;
 
 namespace voe {
@@ skipping 80 matching lines @@
   size_t NumOfChannels() const;
 
  private:
   uint32_t instance_id_;
 
   Atomic32 last_channel_id_;
 
   rtc::CriticalSection lock_;
   std::vector<ChannelOwner> channels_;
 
-  // For generation of random ssrc:s.
-  webrtc::Random random_;
-
   RTC_DISALLOW_COPY_AND_ASSIGN(ChannelManager);
 };
 }  // namespace voe
 }  // namespace webrtc
 
 #endif  // WEBRTC_VOICE_ENGINE_CHANNEL_MANAGER_H