Sort out build dependencies for LinuxUI.

ui/linux_ui/linux_ui_export.h

+// Copyright 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 UI_LINUX_UI_LINUX_UI_EXPORT_H_
+#define UI_LINUX_UI_LINUX_UI_EXPORT_H_
+
+// Defines LINUX_UI_EXPORT so that functionality implemented by the
+// native_theme library can be exported to consumers.
+
+#if defined(COMPONENT_BUILD)
+#if defined(WIN32)
+
+#if defined(LINUX_UI_IMPLEMENTATION)
+#define LINUX_UI_EXPORT __declspec(dllexport)
+#else
+#define LINUX_UI_EXPORT __declspec(dllimport)
+#endif  // defined(LINUX_UI_IMPLEMENTATION)
+
+#else  // !defined(WIN32)
+
+#if defined(LINUX_UI_IMPLEMENTATION)
+#define LINUX_UI_EXPORT __attribute__((visibility("default")))
+#else
+#define LINUX_UI_EXPORT
+#endif
+
+#endif  // defined(WIN32)
+
+#else  // !defined(COMPONENT_BUILD)
+
+#define LINUX_UI_EXPORT
+
+#endif  // defined(COMPONENT_BUILD)
+
+#endif  // UI_LINUX_UI_LINUX_UI_EXPORT_H_