cc: Delay start of scrollbar animation setNeedsRedraw.

cc/scrollbar_animation_controller.h

 // Copyright 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CC_SCROLLBAR_ANIMATION_CONTROLLER_H_
 #define CC_SCROLLBAR_ANIMATION_CONTROLLER_H_
 
 #include "base/time.h"
 #include "cc/base/cc_export.h"
 #include "ui/gfx/vector2d_f.h"
 
 namespace cc {
 
 // This abstract class represents the compositor-side analogy of ScrollbarAnimator.
 // Individual platforms should subclass it to provide specialized implementation.
 class CC_EXPORT ScrollbarAnimationController {
 public:
     virtual ~ScrollbarAnimationController() {}
 
+    virtual bool isScrollGestureInProgress() const = 0;
+    virtual bool isAnimating() const = 0;
+    virtual base::TimeDelta delayBeforeStart(base::TimeTicks now) const = 0;
+
     virtual bool animate(base::TimeTicks) = 0;
-    virtual void didPinchGestureUpdate(base::TimeTicks) = 0;
-    virtual void didPinchGestureEnd(base::TimeTicks) = 0;
-    virtual void didUpdateScrollOffset(base::TimeTicks) = 0;
+    virtual void didScrollGestureBegin() = 0;
+    virtual void didScrollGestureEnd(base::TimeTicks now) = 0;
+    virtual void didProgrammaticallyUpdateScroll(base::TimeTicks now) = 0;
 };
 
 } // namespace cc
 
 #endif  // CC_SCROLLBAR_ANIMATION_CONTROLLER_H_