Move Extension into extensions namespace

chrome/browser/tab_contents/render_view_context_menu.h

Index: chrome/browser/tab_contents/render_view_context_menu.h
diff --git a/chrome/browser/tab_contents/render_view_context_menu.h b/chrome/browser/tab_contents/render_view_context_menu.h
index 94a6441abe1c9657474d309b8256d658efefae5b..4f6323ec0a96a01a640a11e28315862ce6ed7150 100644
--- a/chrome/browser/tab_contents/render_view_context_menu.h
+++ b/chrome/browser/tab_contents/render_view_context_menu.h
@@ -33,6 +33,10 @@ class RenderViewHost;
 class WebContents;
 }
 
+namespace extensions {
+class Extension;
+}
+
 namespace gfx {
 class Point;
 }
@@ -204,7 +208,7 @@ class RenderViewContextMenu : public ui::SimpleMenuModel::Delegate,
       bool can_cross_incognito);
 
   // Gets the extension (if any) associated with the WebContents that we're in.
-  const Extension* GetExtension() const;
+  const extensions::Extension* GetExtension() const;
   void AppendPlatformAppItems();
   void AppendPopupExtensionItems();
   bool AppendCustomItems();