Add test coverage for CrasAudioHandler.

chromeos/audio/audio_devices_pref_handler_stub.h

+// Copyright (c) 2013 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 CHROMEOS_AUDIO_AUDIO_DEVICES_PREF_HANDLER_STUB_H_
+#define CHROMEOS_AUDIO_AUDIO_DEVICES_PREF_HANDLER_STUB_H_
+
+#include "chromeos/audio/audio_devices_pref_handler.h"
+
+#include <map>
+
+namespace chromeos {
+
+struct AudioDevice;
+
+typedef std::map<uint64, bool> AudioDeviceMute;
+typedef std::map<uint64, int> AudioDeviceVolumeGain;
+
+// Stub class for AudioDevicesPrefHandler, used for testing.
+class CHROMEOS_EXPORT AudioDevicesPrefHandlerStub

[rkc, 2013/07/23 20:37:43]

Instead of stubbing this class out, can we instead provide the ability to use a
mock/stub preferences to the main AudioDevicesPrefHandler class?

+    : public AudioDevicesPrefHandler {
+ public:
+  AudioDevicesPrefHandlerStub();
+
+  virtual double GetVolumeGainValue(const AudioDevice& device) OVERRIDE;
+  virtual void SetVolumeGainValue(const AudioDevice& device,
+                                  double value) OVERRIDE;
+  virtual bool GetMuteValue(const AudioDevice& device) OVERRIDE;
+  virtual void SetMuteValue(const AudioDevice& device, bool mute_on) OVERRIDE;
+  virtual bool GetAudioCaptureAllowedValue() OVERRIDE;
+  virtual bool GetAudioOutputAllowedValue() OVERRIDE;
+  virtual void AddAudioPrefObserver(AudioPrefObserver* observer) OVERRIDE;
+  virtual void RemoveAudioPrefObserver(AudioPrefObserver* observer) OVERRIDE;
+
+ protected:
+  virtual ~AudioDevicesPrefHandlerStub();
+
+ private:
+  AudioDeviceMute audio_device_mute_map_;
+  AudioDeviceVolumeGain audio_device_volume_gain_map_;
+
+  DISALLOW_COPY_AND_ASSIGN(AudioDevicesPrefHandlerStub);
+};
+
+}  // namespace chromeos
+
+#endif  // CHROMEOS_AUDIO_AUDIO_DEVICES_PREF_HANDLER_STUB_H_