Make it possible to set the display mode from the WebView API

Source/core/frame/FrameView.h

Index: Source/core/frame/FrameView.h
diff --git a/Source/core/frame/FrameView.h b/Source/core/frame/FrameView.h
index f3a5101aa3e1a58c38b6db075547630b14d8d27b..cf067c818be835060d97c8136f5c7015fe0cf602 100644
--- a/Source/core/frame/FrameView.h
+++ b/Source/core/frame/FrameView.h
@@ -35,6 +35,7 @@
 #include "platform/scroll/ScrollTypes.h"
 #include "platform/scroll/ScrollableArea.h"
 #include "platform/scroll/Scrollbar.h"
+#include "public/platform/WebDisplayMode.h"
 #include "wtf/Forward.h"
 #include "wtf/HashSet.h"
 #include "wtf/OwnPtr.h"
@@ -180,6 +181,9 @@ public:
     void setMediaType(const AtomicString&);
     void adjustMediaTypeForPrinting(bool printing);
 
+    WebDisplayMode displayMode() { return m_displayMode; }
+    void setDisplayMode(WebDisplayMode);
+
     void addSlowRepaintObject();
     void removeSlowRepaintObject();
     bool hasSlowRepaintObjects() const { return m_slowRepaintObjectCount; }
@@ -708,6 +712,8 @@ private:
     // that cannot be delayed until finalization time.
     RefPtrWillBeMember<LocalFrame> m_frame;
 
+    WebDisplayMode m_displayMode;
+
     bool m_doFullPaintInvalidation;
 
     bool m_canHaveScrollbars;