Switch the history backend from using page ids to navigation entry unique ids.

components/history/core/browser/visit_tracker.h

Index: components/history/core/browser/visit_tracker.h
diff --git a/components/history/core/browser/visit_tracker.h b/components/history/core/browser/visit_tracker.h
index 29aefcfadcdce0a30c00b4fb4d719852c53133e7..5687bdc4259bdf32fa2611cfa513bf8337090f44 100644
--- a/components/history/core/browser/visit_tracker.h
+++ b/components/history/core/browser/visit_tracker.h
@@ -26,7 +26,7 @@ class VisitTracker {
   // Notifications -------------------------------------------------------------
 
   void AddVisit(ContextID context_id,
-                int32 page_id,
+                int nav_entry_id,
                 const GURL& url,
                 VisitID visit_id);
 
@@ -39,12 +39,14 @@ class VisitTracker {
   // Returns the visit ID for the transition given information about the visit
   // supplied by the renderer. We will return 0 if there is no appropriate
   // referring visit.
-  VisitID GetLastVisit(ContextID context_id, int32 page_id, const GURL& url);
+  VisitID GetLastVisit(ContextID context_id,
+                       int nav_entry_id,
+                       const GURL& url);
 
  private:
   struct Transition {
     GURL url;          // URL that the event happened to.
-    int32 page_id;     // ID generated by the render process host.
+    int nav_entry_id;  // ID of the navigation entry.
     VisitID visit_id;  // Visit ID generated by history.
   };
   typedef std::vector<Transition> TransitionList;