Refactor preference syncing.

chrome/browser/custom_handlers/protocol_handler_registry.cc

Index: chrome/browser/custom_handlers/protocol_handler_registry.cc
diff --git a/chrome/browser/custom_handlers/protocol_handler_registry.cc b/chrome/browser/custom_handlers/protocol_handler_registry.cc
index 9a9c3e56eff0a05c745c973836a707ef7428a77f..7865822e48a3e7c1da189542d0ee546684ea9506 100644
--- a/chrome/browser/custom_handlers/protocol_handler_registry.cc
+++ b/chrome/browser/custom_handlers/protocol_handler_registry.cc
@@ -245,9 +245,12 @@ void ProtocolHandlerRegistry::OnIgnoreRegisterProtocolHandler(
 }
 
 void ProtocolHandlerRegistry::RegisterPrefs(PrefService* prefService) {
-  prefService->RegisterListPref(prefs::kRegisteredProtocolHandlers);
-  prefService->RegisterListPref(prefs::kIgnoredProtocolHandlers);
-  prefService->RegisterBooleanPref(prefs::kCustomHandlersEnabled, true);
+  prefService->RegisterListPref(prefs::kRegisteredProtocolHandlers,
+                                false /* don't sync pref */);
+  prefService->RegisterListPref(prefs::kIgnoredProtocolHandlers,
+                                false /* don't sync pref */);
+  prefService->RegisterBooleanPref(prefs::kCustomHandlersEnabled, true,
+                                   false /* don't sync pref */);
 }
 
 // Delegate --------------------------------------------------------------------