Activate and inactivate keyboard mic on ChromeOS.

content/browser/renderer_host/media/audio_input_device_manager.h

 // Copyright (c) 2012 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.
 //
 // AudioInputDeviceManager manages the audio input devices. In particular it
 // communicates with MediaStreamManager and AudioInputRendererHost on the
 // browser IO thread, handles queries like
 // enumerate/open/close/GetOpenedDeviceInfoById from MediaStreamManager and
 // GetOpenedDeviceInfoById from AudioInputRendererHost.
 // The work for enumerate/open/close is handled asynchronously on Media Stream
@@ skipping 38 matching lines @@
                         const scoped_refptr<base::SingleThreadTaskRunner>&
                             device_task_runner) OVERRIDE;
   virtual void Unregister() OVERRIDE;
   virtual void EnumerateDevices(MediaStreamType stream_type) OVERRIDE;
   virtual int Open(const StreamDeviceInfo& device) OVERRIDE;
   virtual void Close(int session_id) OVERRIDE;
 
   void UseFakeDevice();
   bool ShouldUseFakeDevice() const;
 
+#if defined(OS_CHROMEOS)
+  // Registers and unregisters that a stream using keyboard mic has been opened
+  // or closed. Keeps count of how many such streams are open and activates and
+  // inactivates the keyboard mic accordingly. The (in)activation is done on the
+  // UI thread and for the register case a callback must therefor be provided
+  // which is called when activated.
+  // Called on the IO thread.
+  void RegisterKeyboardMicStream(const base::Closure& callback);
+  void UnregisterKeyboardMicStream();
+#endif
+
  private:
   // Used by the unittests to get a list of fake devices.
   friend class MediaStreamDispatcherHostTest;
   void GetFakeDeviceNames(media::AudioDeviceNames* device_names);
 
   typedef std::vector<StreamDeviceInfo> StreamDeviceList;
   virtual ~AudioInputDeviceManager();
 
   // Enumerates audio input devices on media stream device thread.
   void EnumerateOnDeviceThread(MediaStreamType stream_type);
@@ skipping 11 matching lines @@
   // referencing the closed device on IO thread.
   void ClosedOnIOThread(MediaStreamType type, int session_id);
 
   // Verifies that the calling thread is media stream device thread.
   bool IsOnDeviceThread() const;
 
   // Helper to return iterator to the device referenced by |session_id|. If no
   // device is found, it will return devices_.end().
   StreamDeviceList::iterator GetDevice(int session_id);
 
+#if defined(OS_CHROMEOS)
+  // Calls Cras audio handler and sets keyboard mic active status.
+  void SetKeyboardMicStreamActiveOnUIThread(bool active);
+#endif
+
   // Only accessed on Browser::IO thread.
   MediaStreamProviderListener* listener_;
   int next_capture_session_id_;
   bool use_fake_device_;
   StreamDeviceList devices_;
 
+#if defined(OS_CHROMEOS)
+  // Keeps count of how many streams are using keyboard mic.
+  int keyboard_mic_streams_count_;
+#endif
+
   media::AudioManager* const audio_manager_;  // Weak.
 
   // The message loop of media stream device thread that this object runs on.
   scoped_refptr<base::SingleThreadTaskRunner> device_task_runner_;
 
   DISALLOW_COPY_AND_ASSIGN(AudioInputDeviceManager);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_RENDERER_HOST_MEDIA_AUDIO_INPUT_DEVICE_MANAGER_H_