components: Move PrefRegistrySyncable into user_prefs namespace.

chrome/browser/search/search.h

Index: chrome/browser/search/search.h
diff --git a/chrome/browser/search/search.h b/chrome/browser/search/search.h
index 5aa81a6334ffbe54eabf63fd6de7b2bf65558f89..32b788ed1a819f27168479d3f28457010e02129c 100644
--- a/chrome/browser/search/search.h
+++ b/chrome/browser/search/search.h
@@ -13,7 +13,6 @@
 #include "base/string16.h"
 
 class GURL;
-class PrefRegistrySyncable;
 class Profile;
 class TemplateURL;
 class TemplateURLRef;
@@ -23,6 +22,10 @@ class NavigationEntry;
 class WebContents;
 }
 
+namespace user_prefs {
+class PrefRegistrySyncable;
+}
+
 namespace chrome {
 
 // Use this value for "start margin" to prevent the "es_sm" parameter from
@@ -72,7 +75,7 @@ bool NavEntryIsInstantNTP(const content::WebContents* contents,
                           const content::NavigationEntry* nav_entry);
 
 // Registers Instant-related user preferences. Called at startup.
-void RegisterInstantUserPrefs(PrefRegistrySyncable* registry);
+void RegisterInstantUserPrefs(user_prefs::PrefRegistrySyncable* registry);
 
 // Returns prefs::kInstantExtendedEnabled in extended mode;
 // prefs::kInstantEnabled otherwise.