Take MT jank into account when animating the scroll offset on CC

cc/animation/scroll_offset_animations_impl.cc

Index: cc/animation/scroll_offset_animations_impl.cc
diff --git a/cc/animation/scroll_offset_animations_impl.cc b/cc/animation/scroll_offset_animations_impl.cc
index 91cb0ab11e27151036e6f8e68b67068419bfbbbe..51f5925a0db3eb0a36a1134b3b448f4917753ada 100644
--- a/cc/animation/scroll_offset_animations_impl.cc
+++ b/cc/animation/scroll_offset_animations_impl.cc
@@ -92,6 +92,26 @@ bool ScrollOffsetAnimationsImpl::ScrollAnimationUpdateTarget(
   return true;
 }
 
+void ScrollOffsetAnimationsImpl::ScrollAnimationAdjustDuration(
+    ElementId element_id,
+    base::TimeDelta adjustment) {
+  if (element_id != scroll_offset_animation_player_->element_id())
+    return;
+
+  if (!scroll_offset_animation_player_->element_animations())
+    return;
+
+  Animation* animation =
+      scroll_offset_animation_player_->element_animations()->GetAnimation(
+          TargetProperty::SCROLL_OFFSET);
+  if (!animation)
+    return;
+
+  ScrollOffsetAnimationCurve* curve =
+      animation->curve()->ToScrollOffsetAnimationCurve();
+  curve->AdjustDuration(adjustment);
+}
+
 void ScrollOffsetAnimationsImpl::ScrollAnimationApplyAdjustment(
     ElementId element_id,
     const gfx::Vector2dF& adjustment) {