Changing animate to beginFrame and use struct rather than naked double to allow extension.

Source/web/PageWidgetDelegate.cpp

Index: Source/web/PageWidgetDelegate.cpp
diff --git a/Source/web/PageWidgetDelegate.cpp b/Source/web/PageWidgetDelegate.cpp
index 68a0070d299b1332cca69ea583c952c5ebbeb4ee..97ce0319f8ff6b9a05c047d531d8bfe07ce35c1b 100644
--- a/Source/web/PageWidgetDelegate.cpp
+++ b/Source/web/PageWidgetDelegate.cpp
@@ -57,13 +57,13 @@ static inline FrameView* mainFrameView(Page* page)
     return page->mainFrame()->view();
 }
 
-void PageWidgetDelegate::animate(Page* page, double monotonicFrameBeginTime)
+void PageWidgetDelegate::animate(Page* page, WebFrameTime frameTime)
 {
     RefPtr<FrameView> view = mainFrameView(page);
     if (!view)
         return;
-    page->autoscrollController().animate(monotonicFrameBeginTime);
-    page->animator().serviceScriptedAnimations(monotonicFrameBeginTime);
+    page->autoscrollController().animate(frameTime);
+    page->animator().serviceScriptedAnimations(frameTime.frameTime());
 }
 
 void PageWidgetDelegate::layout(Page* page)