Add <meta viewport> support to the preloader

Source/core/css/MediaValues.h

Index: Source/core/css/MediaValues.h
diff --git a/Source/core/css/MediaValues.h b/Source/core/css/MediaValues.h
index 4574ae4ce35861f16d567f74d502cc3e3918e7a0..a660b4cabb6aafa2da61bac534888715e5820bf0 100644
--- a/Source/core/css/MediaValues.h
+++ b/Source/core/css/MediaValues.h
@@ -21,11 +21,6 @@ class LocalFrame;
 class CORE_EXPORT MediaValues : public RefCounted<MediaValues> {
 public:
 
-    enum MediaValuesMode {
-        CachingMode,
-        DynamicMode
-    };
-
     virtual ~MediaValues() { }
 
     static PassRefPtr<MediaValues> createDynamicIfFrameExists(LocalFrame*);
@@ -63,6 +58,8 @@ public:
     virtual Document* document() const = 0;
     virtual bool hasValues() const = 0;
 
+    virtual bool isCached() const { return false; }
+
 protected:
     int calculateViewportWidth(LocalFrame*) const;
     int calculateViewportHeight(LocalFrame*) const;