Media Related changes for TabCapture API

content/public/browser/media_observer.h

Index: content/public/browser/media_observer.h
diff --git a/content/public/browser/media_observer.h b/content/public/browser/media_observer.h
index f7ae0dce3547048fa00a84bfcf4a7b4e3ca80c9c..0c98f76cea0f118f1b8f3441965748c1e2779022 100644
--- a/content/public/browser/media_observer.h
+++ b/content/public/browser/media_observer.h
@@ -49,6 +49,13 @@ class MediaObserver {
       int render_view_id,
       const content::MediaStreamDevices& devices) = 0;
 
+  // Called when a media request changes state.
+  virtual void OnMediaRequestStateChanged(
+      int render_process_id,
+      int render_view_id,
+      const content::MediaStreamDevice& device,
+      const content::MediaStreamRequest::RequestState state) = 0;
+
  protected:
   virtual ~MediaObserver() {}
 };