cc: Delay start of scrollbar animation setNeedsRedraw.

cc/scrollbar_animation_controller_linear_fade.cc

Index: cc/scrollbar_animation_controller_linear_fade.cc
diff --git a/cc/scrollbar_animation_controller_linear_fade.cc b/cc/scrollbar_animation_controller_linear_fade.cc
index 89e998def9fda05f61fc404c2f82caaa17e3c18b..cb01b4974ab056c5ca96998494363c27f03173a8 100644
--- a/cc/scrollbar_animation_controller_linear_fade.cc
+++ b/cc/scrollbar_animation_controller_linear_fade.cc
@@ -28,34 +28,38 @@ ScrollbarAnimationControllerLinearFade::~ScrollbarAnimationControllerLinearFade(
 {
 }
 
+double ScrollbarAnimationControllerLinearFade::secondsBeforeStart(base::TimeTicks now) const
+{
+    if (m_lastAwakenTime.is_null())
+        return -1;
+
+    double delta = (now - m_lastAwakenTime).InSecondsF();
+    return std::max(0.0, m_fadeoutDelay - delta);
+}
+
 bool ScrollbarAnimationControllerLinearFade::animate(base::TimeTicks now)
 {
     float opacity = opacityAtTime(now);
     m_scrollLayer->SetScrollbarOpacity(opacity);
-    return opacity;
+    if (!opacity)
+       m_lastAwakenTime = base::TimeTicks();
+    return secondsBeforeStart(now) == 0;
 }
 
 void ScrollbarAnimationControllerLinearFade::didPinchGestureUpdate(base::TimeTicks now)
 {
-    m_pinchGestureInEffect = true;
-}
-
-void ScrollbarAnimationControllerLinearFade::didPinchGestureEnd(base::TimeTicks now)
-{
-    m_pinchGestureInEffect = false;
     m_lastAwakenTime = now;
+    m_scrollLayer->SetScrollbarOpacity(1);
 }
 
 void ScrollbarAnimationControllerLinearFade::didUpdateScrollOffset(base::TimeTicks now)
 {
     m_lastAwakenTime = now;
+    m_scrollLayer->SetScrollbarOpacity(1);
 }
 
 float ScrollbarAnimationControllerLinearFade::opacityAtTime(base::TimeTicks now)
 {
-    if (m_pinchGestureInEffect)
-        return 1;
-
     if (m_lastAwakenTime.is_null())
         return 0;