Add a setting to do frame scrolls through the root layer.

Source/web/WebSettingsImpl.cpp

Index: Source/web/WebSettingsImpl.cpp
diff --git a/Source/web/WebSettingsImpl.cpp b/Source/web/WebSettingsImpl.cpp
index 9bd92a2bd83096016f7ac932f961705e553d907c..94a2bd3d44d7def03674abccf6e9f087b96d394d 100644
--- a/Source/web/WebSettingsImpl.cpp
+++ b/Source/web/WebSettingsImpl.cpp
@@ -241,6 +241,11 @@ void WebSettingsImpl::setReportScreenSizeInPhysicalPixelsQuirk(bool reportScreen
     m_settings->setReportScreenSizeInPhysicalPixelsQuirk(reportScreenSizeInPhysicalPixelsQuirk);
 }
 
+void WebSettingsImpl::setRootLayerScrolls(bool rootLayerScrolls)
+{
+    m_settings->setRootLayerScrolls(rootLayerScrolls);
+}
+
 void WebSettingsImpl::setClobberUserAgentInitialScaleQuirk(bool clobberUserAgentInitialScaleQuirk)
 {
     m_clobberUserAgentInitialScaleQuirk = clobberUserAgentInitialScaleQuirk;