Move Singleton and related structs to namespace base

net/socket/websocket_endpoint_lock_manager.h

Index: net/socket/websocket_endpoint_lock_manager.h
diff --git a/net/socket/websocket_endpoint_lock_manager.h b/net/socket/websocket_endpoint_lock_manager.h
index bddd5455ccfd864befb93f0005c5fdb8ea117dbc..f3887b8cd891407de8735b3ee7ab344c452d1ca9 100644
--- a/net/socket/websocket_endpoint_lock_manager.h
+++ b/net/socket/websocket_endpoint_lock_manager.h
@@ -146,7 +146,7 @@ class NET_EXPORT_PRIVATE WebSocketEndpointLockManager {
   // object.
   base::WeakPtrFactory<WebSocketEndpointLockManager> weak_factory_;
 
-  friend struct DefaultSingletonTraits<WebSocketEndpointLockManager>;
+  friend struct base::DefaultSingletonTraits<WebSocketEndpointLockManager>;
 
   DISALLOW_COPY_AND_ASSIGN(WebSocketEndpointLockManager);
 };