Communicate MT changes to impl-only scroll offset animations

cc/animation/scroll_offset_animations_impl.h

Index: cc/animation/scroll_offset_animations_impl.h
diff --git a/cc/animation/scroll_offset_animations_impl.h b/cc/animation/scroll_offset_animations_impl.h
index 47e6d2b37b1e555c78489e4c351c81a4ffde979e..3ae441995a62636d0f90e641549ba9ec8b328d5e 100644
--- a/cc/animation/scroll_offset_animations_impl.h
+++ b/cc/animation/scroll_offset_animations_impl.h
@@ -40,6 +40,11 @@ class CC_EXPORT ScrollOffsetAnimationsImpl : public AnimationDelegate {
                                    const gfx::ScrollOffset& max_scroll_offset,
                                    base::TimeTicks frame_monotonic_time);
 
+  // Aborts the currently running scroll offset animation on an element and
+  // starts a new one offsetted by adjustment.
+  void ScrollAnimationApplyAdjustment(ElementId element_id,
+                                      const gfx::Vector2dF& adjustment);
+
   void ScrollAnimationAbort(bool needs_completion);
 
   // AnimationDelegate implementation.