Switch AutoscrollController to use animation system instead of timer

Source/web/PageWidgetDelegate.cpp

Index: Source/web/PageWidgetDelegate.cpp
diff --git a/Source/web/PageWidgetDelegate.cpp b/Source/web/PageWidgetDelegate.cpp
index 2f8aa6878ace1d5e098e3ac9bb12c67137f3b265..6bb514ba4dc8f62606bd384023ec42347dd9c6e6 100644
--- a/Source/web/PageWidgetDelegate.cpp
+++ b/Source/web/PageWidgetDelegate.cpp
@@ -34,6 +34,7 @@
 #include "PageOverlayList.h"
 #include "WebInputEvent.h"
 #include "WebInputEventConversion.h"
+#include "core/page/AutoscrollController.h"
 #include "core/page/EventHandler.h"
 #include "core/frame/Frame.h"
 #include "core/frame/FrameView.h"
@@ -59,6 +60,7 @@ void PageWidgetDelegate::animate(Page* page, double monotonicFrameBeginTime)
     FrameView* view = mainFrameView(page);
     if (!view)
         return;
+    page->autoscrollController().animate(monotonicFrameBeginTime);
     view->serviceScriptedAnimations(monotonicFrameBeginTime);
 }