Store audio device's active state in preference

chromeos/audio/cras_audio_handler.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_CRAS_AUDIO_HANDLER_H_
 #define CHROMEOS_AUDIO_CRAS_AUDIO_HANDLER_H_
 
 #include <stddef.h>
 #include <stdint.h>
 #include <queue>
@@ skipping 273 matching lines @@
   // audio nodes unplugged.
   bool NonActiveDeviceUnplugged(size_t old_devices_size,
                                 size_t new_device_size,
                                 uint64_t current_active_node);
 
   // Returns true if there is any device change for for input or output,
   // specified by |is_input|.
   // The new discovered nodes are returned in |new_discovered|.
   bool HasDeviceChange(const AudioNodeList& new_nodes,
                        bool is_input,
-                       AudioNodeList* new_discovered);
+                       AudioDevicePriorityQueue* new_discovered);
 
   // Handles dbus callback for GetNodes.
   void HandleGetNodes(const chromeos::AudioNodeList& node_list, bool success);
 
   // Handles the dbus error callback.
   void HandleGetNodesError(const std::string& error_name,
                            const std::string& error_msg);
 
   // Adds an active node.
   // If there is no active node, |node_id| will be switched to become the
@@ skipping 58 matching lines @@
   bool hdmi_rediscovering_;
 
   base::WeakPtrFactory<CrasAudioHandler> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(CrasAudioHandler);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_AUDIO_CRAS_AUDIO_HANDLER_H_