Revert of Extract webkit_unit_tests from blink_web component.

third_party/WebKit/Source/web/WebExport.h

-// Copyright 2016 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 WebExport_h
-#define WebExport_h
-
-#include "wtf/Compiler.h"
-
-namespace blink {
-
-// This macro is intended to export symbols in Source/web/ which are still
-// private to Blink (for instance, because they are used in unit tests).
-
-#if defined(COMPONENT_BUILD)
-#if defined(WIN32)
-#if BLINK_WEB_IMPLEMENTATION
-#define WEB_EXPORT __declspec(dllexport)
-#else
-#define WEB_EXPORT __declspec(dllimport)
-#endif // BLINK_WEB_IMPLEMENTATION
-#else // defined(WIN32)
-#define WEB_EXPORT __attribute__((visibility("default")))
-#endif
-#else // defined(COMPONENT_BUILD)
-#define WEB_EXPORT
-#endif
-
-} // namespace blink
-
-#endif // WebExport_h