aura: A few changes to have aura_demo compile and run on linux.

aura/aura_export.h

Index: aura/aura_export.h
diff --git a/aura/aura_export.h b/aura/aura_export.h
new file mode 100644
index 0000000000000000000000000000000000000000..1ebab90ca8a2b3f51cd5b938caa4e9b94c1966f1
--- /dev/null
+++ b/aura/aura_export.h
@@ -0,0 +1,30 @@
+// 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.
+
+#ifndef AURA_AURA_EXPORT_H
+#define AURA_AURA_EXPORT_H
+#pragma once
+
+// Defines AURA_EXPORT so that functionality implemented by the aura module
+// can be exported to consumers.
+
+#if defined(COMPONENT_BUILD)
+#if defined(WIN32)
+
+#if defined(AURA_IMPLEMENTATION)
+#define AURA_EXPORT __declspec(dllexport)
+#else
+#define AURA_EXPORT __declspec(dllimport)
+#endif  // defined(AURA_IMPLEMENTATION)
+
+#else  // defined(WIN32)
+#define AURA_EXPORT __attribute__((visibility("default")))
+#endif
+
+#else  // defined(COMPONENT_BUILD)
+#define AURA_EXPORT
+#endif
+
+#endif  // AURA_AURA_EXPORT_H
+