Increment/Decrement capturer count when starts/stops audio capturing.

content/browser/media/capture/web_contents_audio_input_stream.cc

 // Copyright (c) 2013 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.
 
 #include "content/browser/media/capture/web_contents_audio_input_stream.h"
 
 #include <memory>
 #include <string>
 
 #include "base/bind.h"
@@ skipping 60 matching lines @@
   ~Impl() override;
 
   // Notifies the consumer callback that the stream is now dead.
   void ReportError();
 
   // (Re-)Start/Stop mirroring by posting a call to AudioMirroringManager on the
   // IO BrowserThread.
   void StartMirroring();
   void StopMirroring();
 
+  // Increment/decrement the capturer count on the UI BrowserThread.
+  void IncrementCapturerCount();
+  void DecrementCapturerCount();
+
   // Invoked on the UI thread to make sure WebContents muting is turned off for
   // successful audio capture.
   void UnmuteWebContentsAudio();
 
   // AudioMirroringManager::MirroringDestination implementation
   void QueryForMatches(const std::set<SourceFrameRef>& candidates,
                        const MatchesCallback& results_callback) override;
   void QueryForMatchesOnUIThread(const std::set<SourceFrameRef>& candidates,
                                  const MatchesCallback& results_callback);
   media::AudioOutputStream* AddInput(
@@ skipping 67 matching lines @@
 
 bool WebContentsAudioInputStream::Impl::Open() {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   DCHECK_EQ(CONSTRUCTED, state_) << "Illegal to Open more than once.";
 
   if (!mixer_stream_->Open())
     return false;
 
   state_ = OPENED;
-
   tracker_->Start(
       initial_render_process_id_, initial_main_render_frame_id_,
       base::Bind(&Impl::OnTargetChanged, this));
+  BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
+                          base::Bind(&Impl::IncrementCapturerCount, this));
 
   return true;
 }
 
+void WebContentsAudioInputStream::Impl::IncrementCapturerCount() {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+  if (WebContents* contents = tracker_->web_contents())
+    contents->IncrementCapturerCount(gfx::Size());
+}
+
 void WebContentsAudioInputStream::Impl::Start(AudioInputCallback* callback) {
   DCHECK(thread_checker_.CalledOnValidThread());
   DCHECK(callback);
 
   if (state_ != OPENED)
     return;
 
   callback_ = callback;
   if (is_target_lost_) {
     ReportError();
@@ skipping 29 matching lines @@
   StopMirroring();
 }
 
 void WebContentsAudioInputStream::Impl::Close() {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   Stop();
 
   if (state_ == OPENED) {
     state_ = CONSTRUCTED;
+    BrowserThread::PostTask(BrowserThread::UI, FROM_HERE,
+                            base::Bind(&Impl::DecrementCapturerCount, this));
     tracker_->Stop();
     mixer_stream_->Close();
   }
 
   DCHECK_EQ(CONSTRUCTED, state_);
   state_ = CLOSED;
 }
 
+void WebContentsAudioInputStream::Impl::DecrementCapturerCount() {
+  DCHECK_CURRENTLY_ON(BrowserThread::UI);
+
+  if (WebContents* contents = tracker_->web_contents())
+    contents->DecrementCapturerCount();
+}
+
 void WebContentsAudioInputStream::Impl::ReportError() {
   DCHECK(thread_checker_.CalledOnValidThread());
 
   // TODO(miu): Need clean-up of AudioInputCallback interface in a future
   // change, since its only implementation ignores the first argument entirely
   callback_->OnError(NULL);
 }
 
 void WebContentsAudioInputStream::Impl::StartMirroring() {
   DCHECK(thread_checker_.CalledOnValidThread());
@@ skipping 172 matching lines @@
 
 bool WebContentsAudioInputStream::GetAutomaticGainControl() {
   return impl_->mixer_stream()->GetAutomaticGainControl();
 }
 
 bool WebContentsAudioInputStream::IsMuted() {
   return false;
 }
 
 }  // namespace content