Move device/core files to device/base directory.

device/core/device_core_export.h

Index: device/core/device_core_export.h
diff --git a/device/core/device_core_export.h b/device/core/device_core_export.h
deleted file mode 100644
index 6f1cddb19e3eb77668dc7bd1ca66474a45797c2b..0000000000000000000000000000000000000000
--- a/device/core/device_core_export.h
+++ /dev/null
@@ -1,28 +0,0 @@
-// Copyright 2015 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 DEVICE_CORE_DEVICE_CORE_EXPORT_H_
-#define DEVICE_CORE_DEVICE_CORE_EXPORT_H_
-
-#if defined(COMPONENT_BUILD) && defined(WIN32)
-
-#if defined(DEVICE_CORE_IMPLEMENTATION)
-#define DEVICE_CORE_EXPORT __declspec(dllexport)
-#else
-#define DEVICE_CORE_EXPORT __declspec(dllimport)
-#endif
-
-#elif defined(COMPONENT_BUILD) && !defined(WIN32)
-
-#if defined(DEVICE_CORE_IMPLEMENTATION)
-#define DEVICE_CORE_EXPORT __attribute__((visibility("default")))
-#else
-#define DEVICE_CORE_EXPORT
-#endif
-
-#else
-#define DEVICE_CORE_EXPORT
-#endif
-
-#endif  // DEVICE_CORE_DEVICE_CORE_EXPORT_H_