Communicate MT changes to impl-only scroll offset animations

third_party/WebKit/Source/core/layout/ScrollAnchor.cpp

 // Copyright 2015 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.
 
 #include "core/layout/ScrollAnchor.h"
 
 #include "core/frame/FrameView.h"
 #include "core/frame/UseCounter.h"
 #include "core/layout/LayoutView.h"
 #include "core/layout/line/InlineTextBox.h"
@@ skipping 228 matching lines @@
     }
     adjust(adjustment);
 }
 
 void ScrollAnchor::adjust(IntSize adjustment)
 {
     DoublePoint desiredPos = m_scroller->scrollPositionDouble() + adjustment;
     ScrollAnimatorBase* animator = m_scroller->existingScrollAnimator();
     if (!animator || !animator->hasRunningAnimation()) {
         m_scroller->setScrollPosition(desiredPos, AnchoringScroll);
+        animator->updateImplOnlyScrollOffsetAnimation(FloatSize(adjustment));
     } else {
         // If in the middle of a scroll animation, stop the animation, make
         // the adjustment, and continue the animation on the pending delta.
         // TODO(skobes): This is not quite right, we are starting a new curve without
         // saving our progress on the existing curve.
         FloatSize pendingDelta = animator->desiredTargetPosition() -
             FloatPoint(m_scroller->scrollPositionDouble());
         animator->cancelAnimation();
         m_scroller->setScrollPosition(desiredPos, AnchoringScroll);
         animator->userScroll(ScrollByPixel, pendingDelta);
@@ skipping 35 matching lines @@
 
 void ScrollAnchor::notifyRemoved(LayoutObject* layoutObject)
 {
     if (m_current.m_anchorObject == layoutObject)
         m_current.clear();
     if (m_lastAdjusted.m_anchorObject == layoutObject)
         m_lastAdjusted.clear();
 }
 
 } // namespace blink