Speculative revert to see if this change introduced a performance regression on Mac intl perf bots.

chrome/browser/sessions/tab_restore_service.h

Index: chrome/browser/sessions/tab_restore_service.h
===================================================================
--- chrome/browser/sessions/tab_restore_service.h	(revision 150796)
+++ chrome/browser/sessions/tab_restore_service.h	(working copy)
@@ -26,7 +26,6 @@
 namespace content {
 class NavigationController;
 class SessionStorageNamespace;
-class WebContents;
 }
 
 // TabRestoreService is responsible for maintaining the most recently closed
@@ -138,9 +137,9 @@
   void AddObserver(TabRestoreServiceObserver* observer);
   void RemoveObserver(TabRestoreServiceObserver* observer);
 
-  // Creates a Tab to represent |contents| and notifies observers the list of
+  // Creates a Tab to represent |tab| and notifies observers the list of
   // entries has changed.
-  void CreateHistoricalTab(content::WebContents* contents, int index);
+  void CreateHistoricalTab(content::NavigationController* tab, int index);
 
   // Invoked when a browser is closing. If |delegate| is a tabbed browser with
   // at least one tab, a Window is created, added to entries and observers are