Move Extension into extensions namespace

chrome/browser/themes/browser_theme_pack.h

Index: chrome/browser/themes/browser_theme_pack.h
diff --git a/chrome/browser/themes/browser_theme_pack.h b/chrome/browser/themes/browser_theme_pack.h
index 1a5e6489b1b1344d9a4c26809595944b0b905a4e..e582692c9331c3c3481e2082fe197a2ff542ae65 100644
--- a/chrome/browser/themes/browser_theme_pack.h
+++ b/chrome/browser/themes/browser_theme_pack.h
@@ -18,15 +18,22 @@
 #include "ui/gfx/color_utils.h"
 
 class FilePath;
-namespace ui {
-class DataPack;
+
+namespace base {
+class DictionaryValue;
+class RefCountedMemory;
+}
+
+namespace extensions {
+class Extensions;
 }
+
 namespace gfx {
 class Image;
 }
-namespace base {
-class DictionaryValue;
-class RefCountedMemory;
+
+namespace ui {
+class DataPack;
 }
 
 // An optimized representation of a theme, backed by a mmapped DataPack.
@@ -53,7 +60,7 @@ class BrowserThemePack : public base::RefCountedThreadSafe<
   // on a separate thread as it takes so long. This can fail and return NULL in
   // the case where the theme has invalid data.
   static scoped_refptr<BrowserThemePack> BuildFromExtension(
-      const Extension* extension);
+      const extensions::Extension* extension);
 
   // Builds the theme pack from a previously performed WriteToDisk(). This
   // operation should be relatively fast, as it should be an mmap() and some
@@ -118,7 +125,7 @@ class BrowserThemePack : public base::RefCountedThreadSafe<
   virtual ~BrowserThemePack();
 
   // Builds a header ready to write to disk.
-  void BuildHeader(const Extension* extension);
+  void BuildHeader(const extensions::Extension* extension);
 
   // Transforms the JSON tint values into their final versions in the |tints_|
   // array.