[Sync] Rename csync namespace to syncer

sync/notifier/p2p_notifier.cc

Index: sync/notifier/p2p_notifier.cc
diff --git a/sync/notifier/p2p_notifier.cc b/sync/notifier/p2p_notifier.cc
index 548e0f5d54e087c75cc3a29f3bc5c895a5d0fce4..f92cd982bd202f8e03d2e1cc9b70d62c591a1dcb 100644
--- a/sync/notifier/p2p_notifier.cc
+++ b/sync/notifier/p2p_notifier.cc
@@ -14,7 +14,7 @@
 #include "sync/internal_api/public/syncable/model_type_payload_map.h"
 #include "sync/notifier/sync_notifier_observer.h"
 
-namespace csync {
+namespace syncer {
 
 const char* kSyncP2PNotificationChannel = "http://www.google.com/chrome/sync";
 
@@ -289,4 +289,4 @@ void P2PNotifier::SendNotificationData(
   push_client_->SendNotification(notification);
 }
 
-}  // namespace csync
+}  // namespace syncer