Make forward/backward navigation work even when redirection is involved.

chrome/browser/tab_contents/navigation_controller.h

Index: chrome/browser/tab_contents/navigation_controller.h
===================================================================
--- chrome/browser/tab_contents/navigation_controller.h	(revision 15609)
+++ chrome/browser/tab_contents/navigation_controller.h	(working copy)
@@ -424,9 +424,9 @@
   // contents.
   void FinishRestore(int selected_index);
 
-  // Inserts an entry after the current position, removing all entries after it.
-  // The new entry will become the active one.
-  void InsertEntry(NavigationEntry* entry);
+  // Inserts a new entry or replaces the current entry with a new one, removing
+  // all entries after it. The new entry will become the active one.
+  void InsertOrReplaceEntry(NavigationEntry* entry, bool replace);
 
   // Discards the pending and transient entries.
   void DiscardNonCommittedEntriesInternal();