Allow content embedders to create AudioManager.

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 <memory>
 #include <string>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
 #include "base/sequenced_task_runner_helpers.h"
 #include "base/strings/string16.h"
 #include "build/build_config.h"
 #include "media/audio/audio_device_name.h"
 #include "media/audio/audio_logging.h"
 #include "media/base/audio_parameters.h"
 
 namespace base {
 class SingleThreadTaskRunner;
 }
 
 namespace media {
 
 class AudioInputStream;
 class AudioManager;
-class AudioManagerFactory;
 class AudioOutputStream;
 
 class MEDIA_EXPORT AudioManagerDeleter {
  public:
   void operator()(const AudioManager* instance) const;
 };
 using ScopedAudioManagerPtr =
     std::unique_ptr<AudioManager, AudioManagerDeleter>;
 
 // Manages all audio resources.  Provides some convenience functions that avoid
 // the need to provide iterators over the existing streams.
 //
 // Except on OSX, a hang monitor for the audio thread is always created. When a
 // thread hang is detected, it is reported to UMA.  Optionally, if called prior,
 // EnableCrashKeyLoggingForAudioThreadHangs() will cause a non-crash dump to be
 // logged on Windows (this allows us to report driver hangs to Microsoft).
 class MEDIA_EXPORT AudioManager {
  public:
-  // This provides an alternative to the statically linked factory method used
-  // to create AudioManager. This is useful for dynamically-linked third
-  // party clients seeking to provide a platform-specific implementation of
-  // AudioManager. After this is called, all static AudioManager::Create*
-  // methods will return an instance of AudioManager provided by |factory|. This
-  // call may be made at most once per process, and before any calls to static
-  // AudioManager::Create* methods. 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 returned instance must be deleted on AudioManager::GetTaskRunnner().
   //
   // The manager will forward CreateAudioLog() calls to the provided
   // AudioLogFactory; as such |audio_log_factory| must outlive the AudioManager.
   //
   // The manager will use |task_runner| for audio IO. This same task runner
   // is returned by GetTaskRunner().
   // On OS_MACOSX, CoreAudio requires that |task_runner| must belong to the
   // main thread of the process, which in our case is sadly the browser UI
   // thread. Failure to execute calls on the right thread leads to crashes and
   // odd behavior. See http://crbug.com/158170.
   //
   // The manager will use |worker_task_runner| for heavyweight tasks.
   // The |worker_task_runner| may be the same as |task_runner|. This same
   // task runner is returned by GetWorkerTaskRunner.
-  //
-  // If |monitor_task_runner| is not NULL, a monitor will be scheduled on
-  // |monitor_task_runner| to monitor |task_runner|. See EnableHangMonitor().
   static ScopedAudioManagerPtr Create(
       scoped_refptr<base::SingleThreadTaskRunner> task_runner,
       scoped_refptr<base::SingleThreadTaskRunner> worker_task_runner,
-      scoped_refptr<base::SingleThreadTaskRunner> monitor_task_runner,
       AudioLogFactory* audio_log_factory);
 
   // A convenience wrapper of AudioManager::Create for testing.
   // The given |task_runner| is shared for both audio io and heavyweight tasks.
   static ScopedAudioManagerPtr CreateForTesting(
       scoped_refptr<base::SingleThreadTaskRunner> task_runner);
 
+  // Starts monitoring AudioManager task runner for hangs.
+  // Runs the monitor on the given |task_runner|, which must be different from
+  // AudioManager::GetTaskRunner to be meaningful.
+  // This must be called only after an AudioManager instance is created.
+  static void StartHangMonitor(
+      scoped_refptr<base::SingleThreadTaskRunner> task_runner);
+
   // Enables non-crash dumps when audio thread hangs are detected.
   // TODO(dalecurtis): There are no callers to this function at present. A list
   // of bad drivers has been given to Microsoft. This should be re-enabled in
   // the future if Microsoft is able to triage third party drivers.
   // See http://crbug.com/422522
   static void EnableCrashKeyLoggingForAudioThreadHangs();
 
 #if defined(OS_LINUX)
   // Sets the name of the audio source as seen by external apps. Only actually
   // used with PulseAudio as of this writing.
   static void SetGlobalAppName(const std::string& app_name);
 
   // Returns the app name or an empty string if it is not set.
   static const std::string& GetGlobalAppName();
 #endif
 
-  // Should only be used for testing. Resets a previously-set
-  // AudioManagerFactory. The instance of AudioManager is not affected.
-  static void ResetFactoryForTesting();
-
   // 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.
   static AudioManager* Get();
 
   // Returns the localized name of the generic "default" device.
   static std::string GetDefaultDeviceName();
 
   // Returns the localized name of the generic default communications device.
   // This device is not supported on all platforms.
@@ skipping 150 matching lines @@
   friend class base::DeleteHelper<AudioManager>;
 
   scoped_refptr<base::SingleThreadTaskRunner> task_runner_;
   scoped_refptr<base::SingleThreadTaskRunner> worker_task_runner_;
   DISALLOW_COPY_AND_ASSIGN(AudioManager);
 };
 
 }  // namespace media
 
 #endif  // MEDIA_AUDIO_AUDIO_MANAGER_H_