Add AudioStreamRegistry. Move stream counting logic

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 75895e13851c1a422a906eded872a6eff6b4a33f..2858cd99087c4cb8680d3564ac7028592daceb03 100644
--- a/content/browser/renderer_host/render_process_host_impl.h
+++ b/content/browser/renderer_host/render_process_host_impl.h
@@ -23,6 +23,7 @@
 #include "content/browser/child_process_launcher.h"
 #include "content/browser/dom_storage/session_storage_namespace_impl.h"
 #include "content/browser/renderer_host/offscreen_canvas_compositor_frame_sink_provider_impl.h"
+#include "content/browser/renderer_host/media/audio_stream_registry_impl.h"
 #include "content/browser/webrtc/webrtc_eventlog_host.h"
 #include "content/common/associated_interfaces.mojom.h"
 #include "content/common/content_export.h"
@@ -544,6 +545,8 @@ class CONTENT_EXPORT RenderProcessHostImpl
   // through RenderProcessHostObserver::RenderProcessExited.
   bool within_process_died_observer_;
 
+  const AudioStreamRegistryImpl::UniquePtr audio_stream_registry_;
+
   scoped_refptr<AudioRendererHost> audio_renderer_host_;
 
   scoped_refptr<AudioInputRendererHost> audio_input_renderer_host_;