Move Extension into extensions namespace

chrome/browser/chromeos/offline/offline_load_page.h

Index: chrome/browser/chromeos/offline/offline_load_page.h
diff --git a/chrome/browser/chromeos/offline/offline_load_page.h b/chrome/browser/chromeos/offline/offline_load_page.h
index 1e5a78fddd8831c025c067c99924f88671e3f2e7..52fab74260838711fdd46b3319c2bbee996432b3 100644
--- a/chrome/browser/chromeos/offline/offline_load_page.h
+++ b/chrome/browser/chromeos/offline/offline_load_page.h
@@ -14,8 +14,6 @@
 #include "googleurl/src/gurl.h"
 #include "net/base/network_change_notifier.h"
 
-class Extension;
-
 namespace base {
 class DictionaryValue;
 }
@@ -25,6 +23,10 @@ class InterstitialPage;
 class WebContents;
 }
 
+namespace extensions {
+class Extension;
+}
+
 namespace chromeos {
 
 // OfflineLoadPage class shows the interstitial page that is shown
@@ -67,7 +69,7 @@ class OfflineLoadPage : public content::InterstitialPageDelegate,
 
   // Retrieves template strings of the offline page for app and
   // normal site.
-  void GetAppOfflineStrings(const Extension* app,
+  void GetAppOfflineStrings(const extensions::Extension* app,
                             const string16& faield_url,
                             base::DictionaryValue* strings) const;
   void GetNormalOfflineStrings(const string16& faield_url,