Bring back the file dialogs for chrome AURA.

ui/shell_dialogs/shell_dialogs_export.h

Index: ui/shell_dialogs/shell_dialogs_export.h
===================================================================
--- ui/shell_dialogs/shell_dialogs_export.h	(revision 0)
+++ ui/shell_dialogs/shell_dialogs_export.h	(revision 0)
@@ -0,0 +1,33 @@
+// Copyright (c) 2013 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_SHELL_DIALOGS_SHELL_DIALOGS_EXPORT_H_
+#define UI_SHELL_DIALOGS_SHELL_DIALOGS_EXPORT_H_
+
+// Defines SHELL_DIALOGS_EXPORT so that functionality implemented by the Shell
+// Dialogs module can be exported to consumers.
+
+#if defined(COMPONENT_BUILD)
+#if defined(WIN32)
+
+#if defined(SHELL_DIALOGS_IMPLEMENTATION)
+#define SHELL_DIALOGS_EXPORT __declspec(dllexport)
+#else
+#define SHELL_DIALOGS_EXPORT __declspec(dllimport)
+#endif  // defined(SHELL_DIALOGS_IMPLEMENTATION)
+
+#else  // defined(WIN32)
+#if defined(SHELL_DIALOGS_IMPLEMENTATION)
+#define SHELL_DIALOGS_EXPORT __attribute__((visibility("default")))
+#else
+#define SHELL_DIALOGS_EXPORT
+#endif
+#endif
+
+#else  // defined(COMPONENT_BUILD)
+#define SHELL_DIALOGS_EXPORT
+#endif
+
+#endif  // UI_SHELL_DIALOGS_SHELL_DIALOGS_EXPORT_H_
+