Move small c/b/extensions classes into extensions namespace no.1

chrome/browser/ui/webui/extensions/extension_activity_ui.h

Index: chrome/browser/ui/webui/extensions/extension_activity_ui.h
diff --git a/chrome/browser/ui/webui/extensions/extension_activity_ui.h b/chrome/browser/ui/webui/extensions/extension_activity_ui.h
index 19c7ff3e22361e7d95c8a08a77969832c5e189e8..a86cec8b3be2c33c336cc1505a24f42b286b9e4b 100644
--- a/chrome/browser/ui/webui/extensions/extension_activity_ui.h
+++ b/chrome/browser/ui/webui/extensions/extension_activity_ui.h
@@ -5,7 +5,7 @@
 #ifndef CHROME_BROWSER_UI_WEBUI_EXTENSIONS_EXTENSION_ACTIVITY_UI_H_
 #define CHROME_BROWSER_UI_WEBUI_EXTENSIONS_EXTENSION_ACTIVITY_UI_H_
 
-#include "chrome/browser/extensions/extension_activity_log.h"
+#include "chrome/browser/extensions/activity_log.h"
 #include "content/public/browser/web_ui_controller.h"
 
 namespace extensions {
@@ -13,7 +13,7 @@ class Extension;
 }
 
 class ExtensionActivityUI : public content::WebUIController,
-                            public ExtensionActivityLog::Observer {
+                            public extensions::ActivityLog::Observer {
  public:
   explicit ExtensionActivityUI(content::WebUI* web_ui);
   virtual ~ExtensionActivityUI();
@@ -21,9 +21,9 @@ class ExtensionActivityUI : public content::WebUIController,
   // Callback for "requestExtensionData".
   void HandleRequestExtensionData(const base::ListValue* args);
 
-  // ExtensionActivityLog::Observer implementation.
+  // ActivityLog::Observer implementation.
   virtual void OnExtensionActivity(const extensions::Extension* extension,
-                                   ExtensionActivityLog::Activity activity,
+                                   extensions::ActivityLog::Activity activity,
                                    const std::string& msg) OVERRIDE;
 
  private: