Move Extension into extensions namespace

chrome/browser/extensions/extension_management_api.cc

Index: chrome/browser/extensions/extension_management_api.cc
diff --git a/chrome/browser/extensions/extension_management_api.cc b/chrome/browser/extensions/extension_management_api.cc
index fc74f1aede3e5a24ac40a3d8d83f17a753981eab..b22ba2f5a88ac7a37b9c5fa2ed3798d967902857 100644
--- a/chrome/browser/extensions/extension_management_api.cc
+++ b/chrome/browser/extensions/extension_management_api.cc
@@ -40,6 +40,7 @@ using base::IntToString;
 using content::BrowserThread;
 using content::UtilityProcessHost;
 using content::UtilityProcessHostClient;
+using extensions::Extension;
 
 namespace events = extension_event_names;
 namespace keys = extension_management_api_constants;
@@ -489,7 +490,8 @@ void ExtensionManagementEventRouter::Observe(
   } else {
     const Extension* extension = NULL;
     if (event_name == events::kOnExtensionDisabled) {
-      extension = content::Details<UnloadedExtensionInfo>(details)->extension;
+      extension = content::Details<extensions::UnloadedExtensionInfo>(
+          details)->extension;
     } else {
       extension = content::Details<const Extension>(details).ptr();
     }