Build fix for win_aura

ui/aura/aura_constants.cc

Index: ui/aura/aura_constants.cc
diff --git a/ui/aura/aura_constants.cc b/ui/aura/aura_constants.cc
new file mode 100644
index 0000000000000000000000000000000000000000..994a6ea3fbb69fae58d5b8aff39593f6331dd59d
--- /dev/null
+++ b/ui/aura/aura_constants.cc
@@ -0,0 +1,11 @@
+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "ui/aura/aura_constants.h"
+
+namespace aura {
+
+const char* kTooltipTextKey = "TooltipTextKey";
+
+}