Turn webspeech on/off when tab goes fore/background

chrome/browser/media/media_stream_devices_controller.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.
 
 #ifndef CHROME_BROWSER_MEDIA_MEDIA_STREAM_DEVICES_CONTROLLER_H_
 #define CHROME_BROWSER_MEDIA_MEDIA_STREAM_DEVICES_CONTROLLER_H_
 
 #include <map>
 #include <string>
 
@@ skipping 120 matching lines @@
 
   // Return true if the type has been requested and permission is currently set
   // to allowed. Note that it does not reflect the final permission decision.
   // This function is called during the filtering steps to check if the type has
   // been blocked yet or not and the permission may be changed to blocked during
   // these filterings. See also the initialization in the constructor and
   // comments on that.
   bool IsDeviceAudioCaptureRequestedAndAllowed() const;
   bool IsDeviceVideoCaptureRequestedAndAllowed() const;
 
+  // Returns true if media capture device is allowed to be used. This could
+  // return false when tab goes to background.
+  bool IsCaptureDeviceRequestAllowed() const;
+
   content::WebContents* web_contents_;
 
   // The owner of this class needs to make sure it does not outlive the profile.
   Profile* profile_;
 
   // Weak pointer to the tab specific content settings of the tab for which the
   // MediaStreamDevicesController was created. The tab specific content
   // settings are associated with a the web contents of the tab. The
   // MediaStreamDeviceController must not outlive the web contents for which it
   // was created.
@@ skipping 10 matching lines @@
   // passed to the tab specific content settings when the permissions have been
   // resolved. Currently only used by MEDIA_DEVICE_AUDIO_CAPTURE and
   // MEDIA_DEVICE_VIDEO_CAPTURE since those are the only types that require
   // updates in the settings.
   MediaStreamTypeSettingsMap request_permissions_;
 
   DISALLOW_COPY_AND_ASSIGN(MediaStreamDevicesController);
 };
 
 #endif  // CHROME_BROWSER_MEDIA_MEDIA_STREAM_DEVICES_CONTROLLER_H_