Reland Use CopyOnWriteBuffer instead of Buffer to avoid unnecessary copies.

webrtc/api/test/fakedatachannelprovider.h

 /*
  *  Copyright 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.
  */
 
 #ifndef WEBRTC_API_TEST_FAKEDATACHANNELPROVIDER_H_
 #define WEBRTC_API_TEST_FAKEDATACHANNELPROVIDER_H_
 
 #include "webrtc/api/datachannel.h"
 
 class FakeDataChannelProvider : public webrtc::DataChannelProviderInterface {
  public:
   FakeDataChannelProvider()
       : send_blocked_(false),
         transport_available_(false),
         ready_to_send_(false),
         transport_error_(false) {}
   virtual ~FakeDataChannelProvider() {}
 
   bool SendData(const cricket::SendDataParams& params,
-                const rtc::Buffer& payload,
+                const rtc::CopyOnWriteBuffer& payload,
                 cricket::SendDataResult* result) override {
     ASSERT(ready_to_send_ && transport_available_);
     if (send_blocked_) {
       *result = cricket::SDR_BLOCK;
       return false;
     }
 
     if (transport_error_ || payload.size() == 0) {
       *result = cricket::SDR_ERROR;
       return false;
@@ skipping 98 matching lines @@
   cricket::SendDataParams last_send_data_params_;
   bool send_blocked_;
   bool transport_available_;
   bool ready_to_send_;
   bool transport_error_;
   std::set<webrtc::DataChannel*> connected_channels_;
   std::set<uint32_t> send_ssrcs_;
   std::set<uint32_t> recv_ssrcs_;
 };
 #endif  // WEBRTC_API_TEST_FAKEDATACHANNELPROVIDER_H_