Enabled using viewport on desktop browsers behind experimental flag

Source/web/WebSettingsImpl.h

Index: Source/web/WebSettingsImpl.h
diff --git a/Source/web/WebSettingsImpl.h b/Source/web/WebSettingsImpl.h
index e10a0eebbace12e7204b5ea8414e1af64e075233..aa25b684d6bf9d3636c071370ad2de4e67d6d989 100644
--- a/Source/web/WebSettingsImpl.h
+++ b/Source/web/WebSettingsImpl.h
@@ -45,6 +45,7 @@ public:
     virtual ~WebSettingsImpl() { }
 
     virtual bool deviceSupportsTouch();
+    virtual bool anchorScrollPositionOnResize() const;
     virtual bool scrollAnimatorEnabled() const;
     virtual bool touchEditingEnabled() const;
     virtual bool viewportEnabled() const { return m_viewportEnabled; }
@@ -86,6 +87,7 @@ public:
     virtual void setDeferredImageDecodingEnabled(bool);
     virtual void setDeviceSupportsMouse(bool);
     virtual void setDeviceSupportsTouch(bool);
+    virtual void setAnchorScrollPositionOnResize(bool);
     virtual void setDoubleTapToZoomEnabled(bool);
     virtual void setDownloadableBinaryFontsEnabled(bool);
     virtual void setEditableLinkBehaviorNeverLive();
@@ -191,6 +193,7 @@ private:
     bool m_perTilePaintingEnabled;
     bool m_supportDeprecatedTargetDensityDPI;
     int m_pinchOverlayScrollbarThickness;
+    bool m_anchorScrollPositionOnResize;
 };
 
 } // namespace WebKit