Factor out AudioOutputDelegate from AudioRendererHost.

content/browser/renderer_host/media/audio_renderer_host.h

Index: content/browser/renderer_host/media/audio_renderer_host.h
diff --git a/content/browser/renderer_host/media/audio_renderer_host.h b/content/browser/renderer_host/media/audio_renderer_host.h
index afdb31b2b2ab6889a8200f562b056271e6af7ad3..c8e489257441533fa86d8b596465545cbaa2168f 100644
--- a/content/browser/renderer_host/media/audio_renderer_host.h
+++ b/content/browser/renderer_host/media/audio_renderer_host.h
@@ -46,14 +46,18 @@
 #include <memory>
 #include <string>
 #include <utility>
+#include <vector>
 
 #include "base/atomic_ref_count.h"
 #include "base/gtest_prod_util.h"
 #include "base/logging.h"
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
+#include "base/memory/shared_memory.h"
 #include "base/process/process.h"
 #include "base/sequenced_task_runner_helpers.h"
+#include "base/sync_socket.h"
+#include "content/browser/renderer_host/media/audio_output_delegate.h"
 #include "content/browser/renderer_host/media/media_devices_manager.h"
 #include "content/common/content_export.h"
 #include "content/public/browser/browser_message_filter.h"
@@ -79,7 +83,9 @@ class MediaStreamManager;
 class MediaStreamUIProxy;
 class ResourceContext;
 
-class CONTENT_EXPORT AudioRendererHost : public BrowserMessageFilter {
+class CONTENT_EXPORT AudioRendererHost
+    : public BrowserMessageFilter,
+      private AudioOutputDelegate::EventHandler {
  public:
   // Called from UI thread from the owner of this object.
   AudioRendererHost(int render_process_id,
@@ -112,9 +118,6 @@ class CONTENT_EXPORT AudioRendererHost : public BrowserMessageFilter {
   FRIEND_TEST_ALL_PREFIXES(AudioRendererHostTest, CreateMockStream);
   FRIEND_TEST_ALL_PREFIXES(AudioRendererHostTest, MockStreamDataConversation);
 
-  class AudioEntry;
-  typedef std::map<int, AudioEntry*> AudioEntryMap;
-
   // Internal callback type for access requests to output devices.
   // |have_access| is true only if there is permission to access the device.
   typedef base::Callback<void(bool have_access)> OutputDeviceAccessCB;
@@ -129,6 +132,13 @@ class CONTENT_EXPORT AudioRendererHost : public BrowserMessageFilter {
 
   ~AudioRendererHost() override;
 
+  // AudioOutputDelegate::EventHandler implementation
+  void OnStreamCreated(int stream_id,
+                       base::SharedMemory* shared_memory,
+                       base::CancelableSyncSocket* foreign_socket) override;
+  void OnStreamError(int stream_id) override;
+  void OnStreamStateChanged(bool is_playing) override;
+
   // Methods called on IO thread ----------------------------------------------
 
   // Audio related IPC message handlers.
@@ -168,11 +178,6 @@ class CONTENT_EXPORT AudioRendererHost : public BrowserMessageFilter {
 
   // Helper methods.
 
-  // Complete the process of creating an audio stream. This will set up the
-  // shared memory or shared socket in low latency mode and send the
-  // NotifyStreamCreated message to the peer.
-  void DoCompleteCreation(int stream_id);
-
   // Called after the |render_frame_id| provided to OnCreateStream() was
   // validated. When |is_valid| is false, this calls ReportErrorAndClose().
   void DidValidateRenderFrame(int stream_id, bool is_valid);
@@ -186,20 +191,12 @@ class CONTENT_EXPORT AudioRendererHost : public BrowserMessageFilter {
   // Send an error message to the renderer.
   void SendErrorMessage(int stream_id);
 
-  // Delete an audio entry, notifying observers first.  This is called by
-  // AudioOutputController after it has closed.
-  void DeleteEntry(std::unique_ptr<AudioEntry> entry);
-
   // Send an error message to the renderer, then close the stream.
   void ReportErrorAndClose(int stream_id);
 
-  // A helper method to look up a AudioEntry identified by |stream_id|.
-  // Returns NULL if not found.
-  AudioEntry* LookupById(int stream_id);
-
-  // A helper method to update the number of playing streams and alert the
-  // ResourceScheduler when the renderer starts or stops playing an audiostream.
-  void UpdateNumPlayingStreams(AudioEntry* entry, bool is_playing);
+  // A helper method to look up a AudioOutputDelegate identified by |stream_id|.
+  // Returns nullptr if not found.
+  AudioOutputDelegate* LookupById(int stream_id);
 
   // Check if the renderer process has access to the requested output device.
   void CheckOutputDeviceAccess(int render_frame_id,
@@ -256,8 +253,11 @@ class CONTENT_EXPORT AudioRendererHost : public BrowserMessageFilter {
   // Used to access to AudioInputDeviceManager.
   MediaStreamManager* media_stream_manager_;
 
-  // A map of stream IDs to audio sources.
-  AudioEntryMap audio_entries_;
+  using AudioOutputDelegateList =
+      std::vector<std::unique_ptr<AudioOutputDelegate>>;
+
+  // A list of the current open streams.
+  AudioOutputDelegateList delegates_;
 
   // The number of streams in the playing state. Atomic read safe from any
   // thread, but should only be updated from the IO thread.