Remove unused routing ID param from Did(Show|Destroy)FullscreenWidget.

content/public/browser/web_contents_observer.h

Index: content/public/browser/web_contents_observer.h
diff --git a/content/public/browser/web_contents_observer.h b/content/public/browser/web_contents_observer.h
index a3bc77f156426a2ab8c478cec24a5212a73baf6c..1b8f1996095c2a5fa5fac80b1fe1534f5c14b98e 100644
--- a/content/public/browser/web_contents_observer.h
+++ b/content/public/browser/web_contents_observer.h
@@ -401,8 +401,8 @@ class CONTENT_EXPORT WebContentsObserver : public IPC::Listener,
 
   // Invoked when a pepper plugin creates and shows or destroys a fullscreen
   // RenderWidget.
-  virtual void DidShowFullscreenWidget(int routing_id) {}
-  virtual void DidDestroyFullscreenWidget(int routing_id) {}
+  virtual void DidShowFullscreenWidget() {}
+  virtual void DidDestroyFullscreenWidget() {}
 
   // Invoked when the renderer process has toggled the tab into/out of
   // fullscreen mode.