Make the web-animations engine use the passed in blink::WebFrameTime values.

Source/core/page/AutoscrollController.cpp

Index: Source/core/page/AutoscrollController.cpp
diff --git a/Source/core/page/AutoscrollController.cpp b/Source/core/page/AutoscrollController.cpp
index ce0bb8b3c5afacd072f7eb48056fc46fc66ffcd9..5a6fd3b98f3cd21b0f9562d831b22f96ada23176 100644
--- a/Source/core/page/AutoscrollController.cpp
+++ b/Source/core/page/AutoscrollController.cpp
@@ -215,7 +215,7 @@ bool AutoscrollController::panScrollInProgress() const
 
 // FIXME: This would get get better animation fidelity if it used the monotonicFrameBeginTime instead
 // of WTF::currentTime().
-void AutoscrollController::animate(double)
+void AutoscrollController::animate(blink::WebFrameTime frameTime)
 {
     if (!m_autoscrollRenderer) {
         stopAutoscroll();
@@ -225,7 +225,7 @@ void AutoscrollController::animate(double)
     EventHandler& eventHandler = m_autoscrollRenderer->frame()->eventHandler();
     switch (m_autoscrollType) {
     case AutoscrollForDragAndDrop:
-        if (WTF::currentTime() - m_dragAndDropAutoscrollStartTime > autoscrollDelay)
+        if (frameTime.displayFrameTime - m_dragAndDropAutoscrollStartTime > autoscrollDelay)
             m_autoscrollRenderer->autoscroll(m_dragAndDropAutoscrollReferencePosition);
         break;
     case AutoscrollForSelection: