Add <meta viewport> support to the preloader

Source/core/css/MediaValuesCached.h

 // Copyright 2014 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 MediaValuesCached_h
 #define MediaValuesCached_h
 
 #include "core/CoreExport.h"
 #include "core/css/MediaValues.h"
 
@@ skipping 60 matching lines @@
     virtual int availablePointerTypes() const override;
     virtual HoverType primaryHoverType() const override;
     virtual int availableHoverTypes() const override;
     virtual bool threeDEnabled() const override;
     virtual bool strictMode() const override;
     virtual Document* document() const override;
     virtual bool hasValues() const override;
     virtual const String mediaType() const override;
     virtual WebDisplayMode displayMode() const override;
 
+    void setViewportWidth(int);
+    void setViewportHeight(int);
+
+    virtual bool isCached() const override { return true; }
 protected:
     MediaValuesCached();
     MediaValuesCached(LocalFrame*);
     MediaValuesCached(const MediaValuesCachedData&);
 
     MediaValuesCachedData m_data;
 };
 
 } // namespace
 
 #endif // MediaValuesCached_h