components: Move PrefRegistrySyncable into user_prefs namespace.

chrome/browser/net/net_pref_observer.h

Index: chrome/browser/net/net_pref_observer.h
diff --git a/chrome/browser/net/net_pref_observer.h b/chrome/browser/net/net_pref_observer.h
index 37a051adf6b7f92ab7e82e1690674ece3e8086f4..d8c9597ae0386fc3e879a46df4de8bda6c7f0dc9 100644
--- a/chrome/browser/net/net_pref_observer.h
+++ b/chrome/browser/net/net_pref_observer.h
@@ -8,6 +8,8 @@
 #include "base/basictypes.h"
 #include "base/prefs/pref_member.h"
 
+class PrefService;
+
 namespace chrome_browser_net {
 class Predictor;
 }
@@ -16,8 +18,9 @@ namespace prerender {
 class PrerenderManager;
 }
 
-class PrefService;
+namespace user_prefs {
 class PrefRegistrySyncable;
+}
 
 // Monitors network-related preferences for changes and applies them.
 // The supplied PrefService must outlive this NetPrefObserver.
@@ -32,7 +35,7 @@ class NetPrefObserver {
                   chrome_browser_net::Predictor* predictor);
   virtual ~NetPrefObserver();
 
-  static void RegisterUserPrefs(PrefRegistrySyncable* registry);
+  static void RegisterUserPrefs(user_prefs::PrefRegistrySyncable* registry);
 
  private:
   void ApplySettings();