components: Move PrefRegistrySyncable into user_prefs namespace.

chrome/browser/printing/print_dialog_cloud.h

Index: chrome/browser/printing/print_dialog_cloud.h
diff --git a/chrome/browser/printing/print_dialog_cloud.h b/chrome/browser/printing/print_dialog_cloud.h
index 26c4bddde0b1d0db45142384624d3b09996935f7..188ce96575e3a31fbc1e0b05284257b588db38ea 100644
--- a/chrome/browser/printing/print_dialog_cloud.h
+++ b/chrome/browser/printing/print_dialog_cloud.h
@@ -14,7 +14,6 @@
 #include "ui/gfx/native_widget_types.h"
 
 class CommandLine;
-class PrefRegistrySyncable;
 
 namespace base {
 class FilePath;
@@ -24,9 +23,13 @@ namespace content {
 class BrowserContext;
 }
 
+namespace user_prefs {
+class PrefRegistrySyncable;
+}
+
 namespace print_dialog_cloud {
 
-void RegisterUserPrefs(PrefRegistrySyncable* registry);
+void RegisterUserPrefs(user_prefs::PrefRegistrySyncable* registry);
 
 // Creates a print dialog to print a file on disk.
 // Called on the FILE or UI thread. Even though this may start up a modal