Adds method to provide custom AudioManager at runtime.

media/audio/audio_manager.h

Index: media/audio/audio_manager.h
diff --git a/media/audio/audio_manager.h b/media/audio/audio_manager.h
index 5e49b8b399afd138c35f659d73823be06a0e9567..f9118b901481ab37b0928fe859b4fb4ae2076aa1 100644
--- a/media/audio/audio_manager.h
+++ b/media/audio/audio_manager.h
@@ -21,13 +21,20 @@ class SingleThreadTaskRunner;
 namespace media {
 
 class AudioInputStream;
+class AudioManagerFactory;
 class AudioOutputStream;
 
 // Manages all audio resources.  Provides some convenience functions that avoid
 // the need to provide iterators over the existing streams.
 class MEDIA_EXPORT AudioManager {
-  public:
-   virtual ~AudioManager();
+ public:
+  virtual ~AudioManager();
+
+  // Used to override the defualt implementation. After this is called, all

[DaleCurtis, 2015/04/23 16:18:25]

default.

Add some more details about why this is being added: I.e. dynamically linked 3rd
party clients.

[slan, 2015/04/23 18:11:33]

Done.

+  // static AudioManager::Create* methods will return an instance of
+  // AudioManager provided by |factory|. This method takes ownership of
+  // |factory|, which must not be NULL.
+  static void SetFactory(AudioManagerFactory* factory);
 
   // Construct the audio manager; only one instance is allowed.  The manager
   // will forward CreateAudioLog() calls to the provided AudioLogFactory; as
@@ -44,6 +51,10 @@ class MEDIA_EXPORT AudioManager {
   // Similar to Create() except uses a FakeAudioLogFactory for testing.
   static AudioManager* CreateForTesting();
 
+  // Should only be used for testing. Resets a previously-set
+  // AudioManagerFactory. The instance of AudioManager is not affected.
+  static void ResetFactory();

[DaleCurtis, 2015/04/23 16:18:25]

Name it ResetFactoryForTesting, so presubmit catches bad usage.

[slan, 2015/04/23 18:11:33]

Done.

+
   // Returns the pointer to the last created instance, or NULL if not yet
   // created. This is a utility method for the code outside of media directory,
   // like src/chrome.
@@ -130,7 +141,8 @@ class MEDIA_EXPORT AudioManager {
   // Do not free the returned AudioInputStream. It is owned by AudioManager.
   // When you are done with it, call |Stop()| and |Close()| to release it.
   virtual AudioInputStream* MakeAudioInputStream(
-      const AudioParameters& params, const std::string& device_id) = 0;
+      const AudioParameters& params,
+      const std::string& device_id) = 0;
 
   // Returns the task runner used for audio IO.
   virtual scoped_refptr<base::SingleThreadTaskRunner> GetTaskRunner() = 0;