Implement HasInputDevices in CrasAudioManager

chromeos/audio/cras_audio_handler.h

Index: chromeos/audio/cras_audio_handler.h
diff --git a/chromeos/audio/cras_audio_handler.h b/chromeos/audio/cras_audio_handler.h
index 633e30a33a7a2d5d9b4729f747479f23c668b79c..32d2d8317c74b577feb1a78cce695fd4a59c2a4f 100644
--- a/chromeos/audio/cras_audio_handler.h
+++ b/chromeos/audio/cras_audio_handler.h
@@ -21,6 +21,10 @@
 class PrefRegistrySimple;
 class PrefService;
 
+namespace media {
+class AudioManager;
+}
+
 namespace chromeos {
 
 class AudioDevicesPrefHandler;
@@ -63,9 +67,26 @@ class CHROMEOS_EXPORT CrasAudioHandler : public CrasAudioClient::Observer,
     DISALLOW_COPY_AND_ASSIGN(AudioObserver);
   };
 
+  // The wrapper for audio manager methods to be called from this class.
+  // The detail of AudioManager is hidden from CrasAudioHandler.
+  class AudioManagerWrapper {
+   public:
+    virtual ~AudioManagerWrapper();
+    virtual void SetHasInputDevices(bool has_input_devices) = 0;
+
+   protected:
+    AudioManagerWrapper();
+
+   private:
+    DISALLOW_COPY_AND_ASSIGN(AudioManagerWrapper);
+  };
+
   // Sets the global instance. Must be called before any calls to Get().
+  // Optionally pass audio_manager to use implementation other than
+  // AudioManagerWrapperImpl.
   static void Initialize(
-      scoped_refptr<AudioDevicesPrefHandler> audio_pref_handler);
+      scoped_refptr<AudioDevicesPrefHandler> audio_pref_handler,
+      scoped_ptr<AudioManagerWrapper> audio_manager = NULL);

[Daniel Erat, 2015/06/24 13:37:45]

default arguments aren't allowed in cases like this:
https://google-styleguide.googlecode.com/svn/trunk/cppguide.html#Default_Argu...

how about making the audio_manager argument mandatory and just passing in a
concrete implementation of it in the production code?

[cychiang, 2015/06/25 05:45:24]

Done. Change production code at
chrome/browser/chromeos/chrome_browser_main_chromeos.cc.
Also, move AudioManagerWrapperImpl to public of CrasAudioHandler.

 
   // Sets the global instance for testing.
   static void InitializeForTesting();
@@ -190,12 +211,23 @@ class CHROMEOS_EXPORT CrasAudioHandler : public CrasAudioClient::Observer,
 
  protected:
   explicit CrasAudioHandler(

[Daniel Erat, 2015/06/24 13:37:45]

nit: you don't need 'explicit' here now that this has two arguments

[cychiang, 2015/06/25 05:45:24]

Done.

-      scoped_refptr<AudioDevicesPrefHandler> audio_pref_handler);
+      scoped_refptr<AudioDevicesPrefHandler> audio_pref_handler,
+      scoped_ptr<AudioManagerWrapper> audio_manager);
   ~CrasAudioHandler() override;
 
  private:
   friend class CrasAudioHandlerTest;
 
+  class AudioManagerWrapperImpl : public AudioManagerWrapper {
+   public:
+    AudioManagerWrapperImpl();
+    ~AudioManagerWrapperImpl() override;
+    void SetHasInputDevices(bool has_input_devices) override;
+
+   private:
+    DISALLOW_COPY_AND_ASSIGN(AudioManagerWrapperImpl);
+  };
+
   // CrasAudioClient::Observer overrides.
   void AudioClientRestarted() override;
   void NodesChanged() override;
@@ -281,6 +313,12 @@ class CHROMEOS_EXPORT CrasAudioHandler : public CrasAudioClient::Observer,
   void HandleGetNodesError(const std::string& error_name,
                            const std::string& error_msg);
 
+  // Sets HasInputDevice in AudioManager based on the updated device list.
+  void UpdateAudioManagerHasInputDevices();
+
+  // Sets HasInputDevice in AudioManager to true or false.
+  void SetAudioManagerHasInputDevices(bool has_input_devices);
+
   // Adds an active node.
   // If there is no active node, |node_id| will be switched to become the
   // primary active node. Otherwise, it will be added as an additional active
@@ -308,6 +346,10 @@ class CHROMEOS_EXPORT CrasAudioHandler : public CrasAudioClient::Observer,
   scoped_refptr<AudioDevicesPrefHandler> audio_pref_handler_;
   base::ObserverList<AudioObserver> observers_;
 
+  // audio_manager_ will point to an AudioManagerWrapperImpl object or

[Daniel Erat, 2015/06/24 13:37:45]

nit: "will hold" would probably be more accurate than "will point to" now that
this is a scoped_ptr

[cychiang, 2015/06/25 05:45:24]

Done.

+  // a mocked AudioManagerWrapper object for testing.
+  scoped_ptr<CrasAudioHandler::AudioManagerWrapper> audio_manager_;
+
   // Audio data and state.
   AudioDeviceMap audio_devices_;