components: Move PrefRegistrySyncable into user_prefs namespace.

chrome/browser/ui/webui/instant_ui.h

Index: chrome/browser/ui/webui/instant_ui.h
diff --git a/chrome/browser/ui/webui/instant_ui.h b/chrome/browser/ui/webui/instant_ui.h
index f050d132668d0b25606ca8a8462574e6af0aaa7e..3aac9a9718c676fa85b242390245bbb76bbf3859 100644
--- a/chrome/browser/ui/webui/instant_ui.h
+++ b/chrome/browser/ui/webui/instant_ui.h
@@ -7,12 +7,15 @@
 
 #include "content/public/browser/web_ui_controller.h"
 
-class PrefRegistrySyncable;
 
 namespace content {
 class BrowserContext;
 }
 
+namespace user_prefs {
+class PrefRegistrySyncable;
+}
+
 // Provides configuration options for Instant web search and shows debug info.
 class InstantUI : public content::WebUIController {
  public:
@@ -20,7 +23,7 @@ class InstantUI : public content::WebUIController {
   // handlers.
   explicit InstantUI(content::WebUI* web_ui);
 
-  static void RegisterUserPrefs(PrefRegistrySyncable* registry);
+  static void RegisterUserPrefs(user_prefs::PrefRegistrySyncable* registry);
 
  private:
   DISALLOW_COPY_AND_ASSIGN(InstantUI);