Switch AutoscrollController to use animation system instead of timer

Source/core/page/AutoscrollController.h

Index: Source/core/page/AutoscrollController.h
diff --git a/Source/core/page/AutoscrollController.h b/Source/core/page/AutoscrollController.h
index 361581c92cee2eff46f8efe8177cbf06f64dcc02..c66b3a06bc19a35904b5be6cb5d6a693c8713f54 100644
--- a/Source/core/page/AutoscrollController.h
+++ b/Source/core/page/AutoscrollController.h
@@ -26,7 +26,6 @@
 #ifndef AutoscrollController_h
 #define AutoscrollController_h
 
-#include "platform/Timer.h"
 #include "platform/geometry/IntPoint.h"
 #include "wtf/PassOwnPtr.h"
 
@@ -36,6 +35,7 @@ class EventHandler;
 class Frame;
 class FrameView;
 class Node;
+class Page;
 class PlatformMouseEvent;
 class RenderBox;
 class RenderObject;
@@ -53,12 +53,14 @@ enum AutoscrollType {
 // AutscrollController handels autoscroll and pan scroll for EventHandler.
 class AutoscrollController {
 public:
+    static PassOwnPtr<AutoscrollController> create(Page&);
+
+    void animate(double monotonicFrameBeginTime);
     bool autoscrollInProgress() const;
     bool autoscrollInProgress(const RenderBox*) const;
-    static PassOwnPtr<AutoscrollController> create();
     bool panScrollInProgress() const;
     void startAutoscrollForSelection(RenderObject*);
-    void stopAutoscrollTimer();
+    void stopAutoscroll();
     void stopAutoscrollIfNeeded(RenderObject*);
     void updateAutoscrollRenderer();
     void updateDragAndDrop(Node* targetNode, const IntPoint& eventPosition, double eventTime);
@@ -68,14 +70,15 @@ public:
 #endif
 
 private:
-    AutoscrollController();
-    void autoscrollTimerFired(Timer<AutoscrollController>*);
-    void startAutoscrollTimer();
+    explicit AutoscrollController(Page&);
+
+    void startAutoscroll();
+
 #if OS(WIN)
-    void updatePanScrollState(FrameView*, const IntPoint&);
+    void updatePanScrollState(FrameView*, const IntPoint& lastKnownMousePosition);
 #endif
 
-    Timer<AutoscrollController> m_autoscrollTimer;
+    Page& m_page;
     RenderBox* m_autoscrollRenderer;
     AutoscrollType m_autoscrollType;
     IntPoint m_dragAndDropAutoscrollReferencePosition;