Move Extension into extensions namespace

chrome/browser/automation/automation_provider_observers.h

Index: chrome/browser/automation/automation_provider_observers.h
diff --git a/chrome/browser/automation/automation_provider_observers.h b/chrome/browser/automation/automation_provider_observers.h
index af2e2543bf1473599b3950de643fab915d030afc..ceffceeab13f41417764835b5f250cc6d9abe12f 100644
--- a/chrome/browser/automation/automation_provider_observers.h
+++ b/chrome/browser/automation/automation_provider_observers.h
@@ -56,7 +56,6 @@
 class AutomationProvider;
 class BalloonCollection;
 class Browser;
-class Extension;
 class ExtensionProcessManager;
 class ExtensionService;
 class InfoBarTabHelper;
@@ -81,6 +80,10 @@ class RenderViewHost;
 class WebContents;
 }
 
+namespace extensions {
+class Extension;
+}
+
 namespace history {
 class TopSites;
 }
@@ -363,7 +366,7 @@ class ExtensionReadyNotificationObserver
   ExtensionService* service_;
   base::WeakPtr<AutomationProvider> automation_;
   scoped_ptr<IPC::Message> reply_message_;
-  const Extension* extension_;
+  const extensions::Extension* extension_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionReadyNotificationObserver);
 };