Looking up device id by session id for AudioRendererMixerInput

media/base/fake_output_device.h

 // Copyright (c) 2015 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.
 
 #ifndef MEDIA_BASE_FAKE_OUTPUT_DEVICE_H_
 #define MEDIA_BASE_FAKE_OUTPUT_DEVICE_H_
 
 #include <string>
 
 #include "base/macros.h"
 #include "media/base/output_device.h"
 
 namespace media {
 
 class FakeOutputDevice : public OutputDevice {
  public:
   FakeOutputDevice();
   explicit FakeOutputDevice(OutputDeviceStatus status);
+  FakeOutputDevice(OutputDeviceStatus status, const AudioParameters& params);
   ~FakeOutputDevice() override;
 
   // OutputDevice implementation.
   void SwitchOutputDevice(const std::string& device_id,
                           const url::Origin& security_origin,
                           const SwitchOutputDeviceCB& callback) override;
   AudioParameters GetOutputParameters() override;
   OutputDeviceStatus GetDeviceStatus() override;
 
  private:
-  OutputDeviceStatus device_status_;
+  const OutputDeviceStatus status_;
+  const AudioParameters params_;
   DISALLOW_COPY_AND_ASSIGN(FakeOutputDevice);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_BASE_FAKE_OUTPUT_DEVICE_H_