Small refactor to media architecture in order to allow end-to-end tests.

media/audio/audio_manager.h

 // Copyright (c) 2012 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_AUDIO_AUDIO_MANAGER_H_
 #define MEDIA_AUDIO_AUDIO_MANAGER_H_
 
 #include <string>
 
 #include "base/basictypes.h"
@@ skipping 17 matching lines @@
 // objects. Provides some convenience functions that avoid the need to provide
 // iterators over the existing streams.
 class MEDIA_EXPORT AudioManager {
  public:
   virtual ~AudioManager();
 
   // Use to construct the audio manager.
   // NOTE: There should only be one instance.
   static AudioManager* Create();
 
+  // For testing purposes only: sets the testing AudioManager that will be
+  // returned by subsequent invocations of the Create method.
+  static void set_audio_manager_for_tests(AudioManager* audio_manager);

[tommi (sloooow) - chröme, 2012/07/11 09:59:08]

Can you explain why you need this? I would like to avoid going down the route of
having global variables and static methods even if it's for tests only.
Can't you just inject your own AudioManager instance into the classes you want
to test?

+
   // Returns true if the OS reports existence of audio devices. This does not
   // guarantee that the existing devices support all formats and sample rates.
   virtual bool HasAudioOutputDevices() = 0;
 
   // Returns true if the OS reports existence of audio recording devices. This
   // does not guarantee that the existing devices support all formats and
   // sample rates.
   virtual bool HasAudioInputDevices() = 0;
 
   // Returns a human readable string for the model/make of the active audio
@@ skipping 69 matching lines @@
   // Returns message loop used for audio IO.
   virtual scoped_refptr<base::MessageLoopProxy> GetMessageLoop() = 0;
 
  protected:
   AudioManager();
 
   // Called from Create() to initialize the instance.
   virtual void Init() = 0;
 
  private:
+  static AudioManager* audio_manager_for_tests_;
+
   DISALLOW_COPY_AND_ASSIGN(AudioManager);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_AUDIO_MANAGER_H_