Strip out stream counting from AudioRendererHost.

content/browser/renderer_host/render_process_host_impl.h

Index: content/browser/renderer_host/render_process_host_impl.h
diff --git a/content/browser/renderer_host/render_process_host_impl.h b/content/browser/renderer_host/render_process_host_impl.h
index dc269f22f81e0de9e99767e95c6d651588c93ff4..df64f9219bde3ea510acad90a5765668b666f9a8 100644
--- a/content/browser/renderer_host/render_process_host_impl.h
+++ b/content/browser/renderer_host/render_process_host_impl.h
@@ -32,6 +32,7 @@
 #include "content/public/common/service_manager_connection.h"
 #include "ipc/ipc_channel_proxy.h"
 #include "ipc/ipc_platform_file.h"
+#include "media/audio/audio_streams_tracker.h"
 #include "media/media_features.h"
 #include "mojo/public/cpp/bindings/associated_binding.h"
 #include "mojo/public/cpp/bindings/associated_binding_set.h"
@@ -123,7 +124,6 @@ class CONTENT_EXPORT RenderProcessHostImpl
   void WidgetRestored() override;
   void WidgetHidden() override;
   int VisibleWidgetCount() const override;
-  void AudioStateChanged() override;
   bool IsForGuestsOnly() const override;
   StoragePartition* GetStoragePartition() const override;
   bool Shutdown(int exit_code, bool wait) override;
@@ -287,6 +287,15 @@ class CONTENT_EXPORT RenderProcessHostImpl
 
   void RecomputeAndUpdateWebKitPreferences();
 
+  // Called when an audio stream is added or removed and used to determine if
+  // the process should be backgrounded or not.
+  //
+  // TODO(dalecurtis, maxmorin): Currently this only checks if a stream is
+  // playing or not, but instead it should be based on if the stream is audible
+  // or not.
+  void OnAudioStreamAdded();
+  void OnAudioStreamRemoved();
+
  protected:
   // A proxy for our IPC::Channel that lives on the IO thread.
   std::unique_ptr<IPC::ChannelProxy> channel_;
@@ -599,6 +608,10 @@ class CONTENT_EXPORT RenderProcessHostImpl
   mojom::RouteProviderAssociatedPtr remote_route_provider_;
   mojom::RendererAssociatedPtr renderer_interface_;
 
+  // Tracks active audio streams within the render process; used to determine if
+  // if a process should be backgrounded.
+  media::AudioStreamsTracker audio_streams_tracker_;
+
   // A WeakPtrFactory which is reset every time Cleanup() runs. Used to vend
   // WeakPtrs which are invalidated any time the RPHI is recycled.
   std::unique_ptr<base::WeakPtrFactory<RenderProcessHostImpl>>