Changes to add duration into history database.

chrome/browser/history/history_tab_helper.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/history/history_tab_helper.h"
 
 #include <utility>
 
 #include "chrome/browser/history/history.h"
 #include "chrome/browser/history/top_sites.h"
@@ skipping 153 matching lines @@
 }
 
 HistoryService* HistoryTabHelper::GetHistoryService() {
   Profile* profile =
       Profile::FromBrowserContext(web_contents()->GetBrowserContext());
   if (profile->IsOffTheRecord())
     return NULL;
 
   return profile->GetHistoryService(Profile::IMPLICIT_ACCESS);
 }
+
+void HistoryTabHelper::WebContentsDestroyed(WebContents* tab) {
+  // We update the history for this URL.
+  // The content returned from web_contents() has been destroyed by now.
+  // We need to use tab value directly.

[GeorgeY, 2012/03/27 21:15:57]

May be
// We need to use tab value directly as a hash.
To indicate that it is used as a weak pointer?

[Wei Li, 2012/03/27 23:01:50]

It is not used as a hash, but a pointer as it passes in.

+  Profile* profile = Profile::FromBrowserContext(tab->GetBrowserContext());
+  if (profile->IsOffTheRecord())
+    return;
+
+  HistoryService* hs = profile->GetHistoryService(Profile::IMPLICIT_ACCESS);
+  if (hs) {
+    NavigationEntry* entry = tab->GetController().GetLastCommittedEntry();
+    if (entry) {
+      hs->UpdateDBWithPageInfo(tab, entry->GetPageID(), tab->GetURL(),
+                               base::Time::Now());
+    }
+  }
+}