Move Extension into extensions namespace

chrome/browser/extensions/extension_cookies_helpers.h

Index: chrome/browser/extensions/extension_cookies_helpers.h
diff --git a/chrome/browser/extensions/extension_cookies_helpers.h b/chrome/browser/extensions/extension_cookies_helpers.h
index b2f2c05b7292867dec3cf503c6ee117d6df98a9d..aa282bee672d1d9c89716fa565a8c555c238f03a 100644
--- a/chrome/browser/extensions/extension_cookies_helpers.h
+++ b/chrome/browser/extensions/extension_cookies_helpers.h
@@ -16,7 +16,6 @@
 #include "net/cookies/cookie_monster.h"
 
 class Browser;
-class Extension;
 class Profile;
 
 namespace base {
@@ -24,6 +23,10 @@ class DictionaryValue;
 class ListValue;
 }
 
+namespace extensions {
+class Extension;
+}
+
 namespace extension_cookies_helpers {
 
 // Returns either the original profile or the incognito profile, based on the
@@ -70,7 +73,7 @@ void AppendMatchingCookiesToList(
     const net::CookieList& all_cookies,
     const std::string& store_id,
     const GURL& url, const base::DictionaryValue* details,
-    const Extension* extension,
+    const extensions::Extension* extension,
     base::ListValue* match_list);
 
 // Appends the IDs of all tabs belonging to the given browser to the