Set keyboard mic effect if available.

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 75 matching lines @@
   // 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);
 
   // Only accessed on Browser::IO thread.
   MediaStreamProviderListener* listener_;
   int next_capture_session_id_;
   bool use_fake_device_;
   StreamDeviceList devices_;
 
+#if defined(OS_CHROMEOS)
+  // Flag that's set when we have checked if the system has a keyboard mic. We
+  // only need to check it once, and not when constructing since that will
+  // affect startup time.
+  // Must be accessed on the IO thread;
+  bool has_checked_keyboard_mic_;
+#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_