Componentization: make core/dom visible for blink_web and blink_tests.

Source/core/dom/ViewportDescription.h

 /*
  * Copyright (C) 1999 Lars Knoll (knoll@kde.org)
  *           (C) 1999 Antti Koivisto (koivisto@kde.org)
  *           (C) 2001 Dirk Mueller (mueller@kde.org)
  *           (C) 2006 Alexey Proskuryakov (ap@webkit.org)
  * Copyright (C) 2004, 2005, 2006, 2007, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Torch Mobile Inc. All rights reserved. (http://www.torchmobile.com/)
  * Copyright (C) 2010 Nokia Corporation and/or its subsidiary(-ies)
  * Copyright (C) 2012-2013 Intel Corporation. All rights reserved.
  *
@@ skipping 10 matching lines @@
  * You should have received a copy of the GNU Library General Public License
  * along with this library; see the file COPYING.LIB.  If not, write to
  * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  * Boston, MA 02110-1301, USA.
  *
  */
 
 #ifndef ViewportDescription_h
 #define ViewportDescription_h
 
+#include "core/CoreExport.h"
 #include "core/page/PageScaleConstraints.h"
 #include "platform/Length.h"
 #include "platform/geometry/FloatSize.h"
 
 namespace blink {
 
 class LocalFrame;
 
-struct ViewportDescription {
+struct CORE_EXPORT ViewportDescription {
 
     enum Type {
         // These are ordered in increasing importance.
         UserAgentStyleSheet,
         HandheldFriendlyMeta,
         MobileOptimizedMeta,
         ViewportMeta,
         AuthorStyleSheet
     } type;
 
@@ skipping 80 matching lines @@
     void reportMobilePageStats(const LocalFrame*) const;
 
 private:
     enum Direction { Horizontal, Vertical };
     static float resolveViewportLength(const Length&, const FloatSize& initialViewportSize, Direction);
 };
 
 } // namespace blink
 
 #endif // ViewportDescription_h