Add AudioStreamRegistry. Move stream counting logic

content/browser/renderer_host/render_process_host_impl.cc

Index: content/browser/renderer_host/render_process_host_impl.cc
diff --git a/content/browser/renderer_host/render_process_host_impl.cc b/content/browser/renderer_host/render_process_host_impl.cc
index 5948e63c9a409613478ea7abe13bd13270ac8123..eb59eabb5618b4f8f506d58330e27bffb0f9b94c 100644
--- a/content/browser/renderer_host/render_process_host_impl.cc
+++ b/content/browser/renderer_host/render_process_host_impl.cc
@@ -101,6 +101,7 @@
 #include "content/browser/renderer_host/file_utilities_message_filter.h"
 #include "content/browser/renderer_host/media/audio_input_renderer_host.h"
 #include "content/browser/renderer_host/media/audio_renderer_host.h"
+#include "content/browser/renderer_host/media/audio_stream_registry_impl.h"
 #include "content/browser/renderer_host/media/media_stream_dispatcher_host.h"
 #include "content/browser/renderer_host/media/peer_connection_tracker_host.h"
 #include "content/browser/renderer_host/media/video_capture_host.h"
@@ -677,6 +678,7 @@ RenderProcessHostImpl::RenderProcessHostImpl(
       gpu_observer_registered_(false),
       delayed_cleanup_needed_(false),
       within_process_died_observer_(false),
+      audio_stream_registry_(new AudioStreamRegistryImpl(id_)),

[o1ka, 2016/12/16 09:48:16]

It would be cleaner to have a factory method in AudioStreamRegistry.

[Max Morin, 2016/12/19 16:29:03]

Done. The interface in AudioStreamRegistry is for registering streams, so I
added the factory function to AudioStreamRegistryImpl instead (which also has
HasActiveAudio and will have debug recording control later).

 #if BUILDFLAG(ENABLE_WEBRTC)
       webrtc_eventlog_host_(id_),
 #endif
@@ -1069,8 +1071,8 @@ void RenderProcessHostImpl::CreateMessageFilters() {
       BrowserMainLoop::GetInstance()->user_input_monitor());
   AddFilter(audio_input_renderer_host_.get());
   audio_renderer_host_ = new AudioRendererHost(
-      GetID(), audio_manager, AudioMirroringManager::GetInstance(),
-      media_stream_manager,
+      GetID(), audio_stream_registry_.get(), audio_manager,
+      AudioMirroringManager::GetInstance(), media_stream_manager,
       browser_context->GetResourceContext()->GetMediaDeviceIDSalt());
   AddFilter(audio_renderer_host_.get());
   AddFilter(
@@ -2761,7 +2763,7 @@ void RenderProcessHostImpl::UpdateProcessPriority() {
   // visible widgets -- the callers must call this function whenever we
   // transition in/out of those states.
   const bool should_background =
-      visible_widgets_ == 0 && !audio_renderer_host_->HasActiveAudio() &&
+      visible_widgets_ == 0 && !audio_stream_registry_->HasActiveAudio() &&
       !base::CommandLine::ForCurrentProcess()->HasSwitch(
           switches::kDisableRendererBackgrounding);