Bindings for CSSOM View smooth scroll API

Source/platform/scroll/ScrollableArea.cpp

Index: Source/platform/scroll/ScrollableArea.cpp
diff --git a/Source/platform/scroll/ScrollableArea.cpp b/Source/platform/scroll/ScrollableArea.cpp
index 5fbbfbbd03dfdf50afa858a83ae473712a5c25e5..1a2ff4288d4088308386510b88b1aacbf20f252c 100644
--- a/Source/platform/scroll/ScrollableArea.cpp
+++ b/Source/platform/scroll/ScrollableArea.cpp
@@ -188,6 +188,20 @@ void ScrollableArea::scrollPositionChanged(const IntPoint& position)
         scrollAnimator()->notifyContentAreaScrolled(scrollPosition() - oldPosition);
 }
 
+bool ScrollableArea::scrollBehaviorFromString(const String& behaviorString, ScrollBehavior& behavior)
+{
+    if (behaviorString == "auto")
+        behavior = ScrollBehaviorAuto;
+    else if (behaviorString == "instant")
+        behavior = ScrollBehaviorInstant;
+    else if (behaviorString == "smooth")
+        behavior = ScrollBehaviorSmooth;
+    else
+        return false;
+
+    return true;
+}
+
 bool ScrollableArea::handleWheelEvent(const PlatformWheelEvent& wheelEvent)
 {
     return scrollAnimator()->handleWheelEvent(wheelEvent);