Implement a salt for MediaSource IDs that can be cleared by a user.

content/test/webrtc_audio_device_test.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "content/test/webrtc_audio_device_test.h"
 
 #include "base/bind.h"
 #include "base/bind_helpers.h"
 #include "base/compiler_specific.h"
 #include "base/file_util.h"
@@ skipping 156 matching lines @@
   }
 
   virtual bool AllowMicAccess(const GURL& origin) OVERRIDE {
     return false;
   }
 
   virtual bool AllowCameraAccess(const GURL& origin) OVERRIDE {
     return false;
   }
 
+  virtual std::string GetMediaDeviceIDSalt() OVERRIDE {
+    return "";
+  }
+
  private:
   net::URLRequestContext* test_request_context_;
 
   DISALLOW_COPY_AND_ASSIGN(MockRTCResourceContext);
 };
 
 ACTION_P(QuitMessageLoop, loop_or_proxy) {
   loop_or_proxy->PostTask(FROM_HERE, base::MessageLoop::QuitClosure());
 }
 
@@ skipping 254 matching lines @@
 int WebRTCTransportImpl::SendPacket(int channel, const void* data, int len) {
   return network_->ReceivedRTPPacket(channel, data, len);
 }
 
 int WebRTCTransportImpl::SendRTCPPacket(int channel, const void* data,
                                         int len) {
   return network_->ReceivedRTCPPacket(channel, data, len);
 }
 
 }  // namespace content