Turn webspeech on/off when tab goes fore/background

chrome/browser/media/media_stream_devices_controller.h

Index: chrome/browser/media/media_stream_devices_controller.h
diff --git a/chrome/browser/media/media_stream_devices_controller.h b/chrome/browser/media/media_stream_devices_controller.h
index c5325dfef192b18331b4402668ef1eb8bf7a7199..01e68492e00048f931d6047c6d89d233d3909aa3 100644
--- a/chrome/browser/media/media_stream_devices_controller.h
+++ b/chrome/browser/media/media_stream_devices_controller.h
@@ -138,6 +138,10 @@ class MediaStreamDevicesController : public PermissionBubbleRequest {
   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.