diff --git a/libweave/external/base/base_export.h b/libweave/external/base/base_export.h
new file mode 100644
index 0000000..723b38a
--- /dev/null
+++ b/libweave/external/base/base_export.h
@@ -0,0 +1,34 @@
+// Copyright (c) 2012 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.
+
+#ifndef BASE_BASE_EXPORT_H_
+#define BASE_BASE_EXPORT_H_
+
+#if defined(COMPONENT_BUILD)
+#if defined(WIN32)
+
+#if defined(BASE_IMPLEMENTATION)
+#define BASE_EXPORT __declspec(dllexport)
+#define BASE_EXPORT_PRIVATE __declspec(dllexport)
+#else
+#define BASE_EXPORT __declspec(dllimport)
+#define BASE_EXPORT_PRIVATE __declspec(dllimport)
+#endif  // defined(BASE_IMPLEMENTATION)
+
+#else  // defined(WIN32)
+#if defined(BASE_IMPLEMENTATION)
+#define BASE_EXPORT __attribute__((visibility("default")))
+#define BASE_EXPORT_PRIVATE __attribute__((visibility("default")))
+#else
+#define BASE_EXPORT
+#define BASE_EXPORT_PRIVATE
+#endif  // defined(BASE_IMPLEMENTATION)
+#endif
+
+#else  // defined(COMPONENT_BUILD)
+#define BASE_EXPORT
+#define BASE_EXPORT_PRIVATE
+#endif
+
+#endif  // BASE_BASE_EXPORT_H_