Reduce chrome cras dbus call logs during device rebooting.

chromeos/dbus/cras_audio_client.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_DBUS_CRAS_AUDIO_CLIENT_H_
 #define CHROMEOS_DBUS_CRAS_AUDIO_CLIENT_H_
 
 #include "base/callback.h"
 #include "base/observer_list.h"
 #include "chromeos/chromeos_export.h"
@@ skipping 45 matching lines @@
   // 2 arguments, |volume_state| which containing both input and  output volume
   // state data, and |success| which indicates whether or not the request
   // succeeded.
   typedef base::Callback<void(const VolumeState&, bool)> GetVolumeStateCallback;
 
   // GetNodesCallback is used for GetNodes method. It receives 2 arguments,
   // |audio_nodes| which containing a list of audio nodes data and
   // |success| which indicates whether or not the request succeeded.
   typedef base::Callback<void(const AudioNodeList&, bool)> GetNodesCallback;
 
+  // ErrorCallback is used for cras dbus method error response. It receives 2
+  // arguments, |error_name| indicates the dbus error name, and |error_message|
+  // contains the detailed dbus error message.
+  typedef base::Callback<void(const std::string&,
+                              const std::string&)> ErrorCallback;
+
   // Gets the volume state, asynchronously.
   virtual void GetVolumeState(const GetVolumeStateCallback& callback) = 0;
 
   // Gets an array of audio input and output nodes.
-  virtual void GetNodes(const GetNodesCallback& callback) = 0;
+  virtual void GetNodes(const GetNodesCallback& callback,
+                        const ErrorCallback& error_callback) = 0;
 
   // Sets output volume of the given |node_id| to |volume|, in the rage of
   // [0, 100].
   virtual void SetOutputNodeVolume(uint64 node_id, int32 volume) = 0;
 
   // Sets output mute from user action.
   virtual void SetOutputUserMute(bool mute_on) = 0;
 
   // Sets input gain of the given |node_id| to |gain|, in the range of
   // [0, 100].
@@ skipping 16 matching lines @@
   CrasAudioClient();
 
  private:
 
   DISALLOW_COPY_AND_ASSIGN(CrasAudioClient);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROMEOS_DBUS_CRAS_AUDIO_CLIENT_H_