*** NOT FOR LANDING *** mapLocalToContainer and offsetFromContainer cleanup.

Source/core/layout/LayoutBox.cpp

Index: Source/core/layout/LayoutBox.cpp
diff --git a/Source/core/layout/LayoutBox.cpp b/Source/core/layout/LayoutBox.cpp
index aaf15908b75400b2c123c6183c0c7757ec23d129..026fd703ed84d465992bd41a79cfe1c8f31d9d67 100644
--- a/Source/core/layout/LayoutBox.cpp
+++ b/Source/core/layout/LayoutBox.cpp
@@ -1558,60 +1558,6 @@ LayoutUnit LayoutBox::perpendicularContainingBlockLogicalHeight() const
     return cb->adjustContentBoxLogicalHeightForBoxSizing(logicalHeightLength.value());
 }
 
-void LayoutBox::mapLocalToContainer(const LayoutBoxModelObject* paintInvalidationContainer, TransformState& transformState, MapCoordinatesFlags mode, bool* wasFixed, const PaintInvalidationState* paintInvalidationState) const
-{
-    if (paintInvalidationContainer == this)
-        return;
-
-    if (paintInvalidationState && paintInvalidationState->canMapToContainer(paintInvalidationContainer)) {
-        LayoutSize offset = paintInvalidationState->paintOffset() + locationOffset();
-        if (style()->hasInFlowPosition() && layer())
-            offset += layer()->offsetForInFlowPosition();
-        transformState.move(offset);
-        return;
-    }
-
-    bool containerSkipped;
-    LayoutObject* o = container(paintInvalidationContainer, &containerSkipped);
-    if (!o)
-        return;
-
-    bool isFixedPos = style()->position() == FixedPosition;
-    bool hasTransform = hasLayer() && layer()->transform();
-    // If this box has a transform, it acts as a fixed position container for fixed descendants,
-    // and may itself also be fixed position. So propagate 'fixed' up only if this box is fixed position.
-    if (hasTransform && !isFixedPos)
-        mode &= ~IsFixed;
-    else if (isFixedPos)
-        mode |= IsFixed;
-
-    if (wasFixed)
-        *wasFixed = mode & IsFixed;
-
-    LayoutSize containerOffset = offsetFromContainer(o, roundedLayoutPoint(transformState.mappedPoint()));
-
-    bool preserve3D = mode & UseTransforms && (o->style()->preserves3D() || style()->preserves3D());
-    if (mode & UseTransforms && shouldUseTransformFromContainer(o)) {
-        TransformationMatrix t;
-        getTransformFromContainer(o, containerOffset, t);
-        transformState.applyTransform(t, preserve3D ? TransformState::AccumulateTransform : TransformState::FlattenTransform);
-    } else {
-        transformState.move(containerOffset.width(), containerOffset.height(), preserve3D ? TransformState::AccumulateTransform : TransformState::FlattenTransform);
-    }
-
-    if (containerSkipped) {
-        // There can't be a transform between paintInvalidationContainer and o, because transforms create containers, so it should be safe
-        // to just subtract the delta between the paintInvalidationContainer and o.
-        LayoutSize containerOffset = paintInvalidationContainer->offsetFromAncestorContainer(o);
-        transformState.move(-containerOffset.width(), -containerOffset.height(), preserve3D ? TransformState::AccumulateTransform : TransformState::FlattenTransform);
-        return;
-    }
-
-    mode &= ~ApplyContainerFlip;
-
-    o->mapLocalToContainer(paintInvalidationContainer, transformState, mode, wasFixed);
-}
-
 void LayoutBox::mapAbsoluteToLocalPoint(MapCoordinatesFlags mode, TransformState& transformState) const
 {
     bool isFixedPos = style()->position() == FixedPosition;
@@ -1627,34 +1573,14 @@ void LayoutBox::mapAbsoluteToLocalPoint(MapCoordinatesFlags mode, TransformState
     LayoutBoxModelObject::mapAbsoluteToLocalPoint(mode, transformState);
 }
 
-LayoutSize LayoutBox::offsetFromContainer(const LayoutObject* o, const LayoutPoint& point, bool* offsetDependsOnPoint) const
+LayoutSize LayoutBox::offsetFromContainer(const LayoutObject* o) const
 {
-    ASSERT(o == container());
-
-    LayoutSize offset;
-    if (isRelPositioned())
-        offset += offsetForInFlowPosition();
-
-    if (!isInline() || isReplaced()) {
-        offset += topLeftLocationOffset();
-        if (o->isLayoutFlowThread()) {
-            // So far the point has been in flow thread coordinates (i.e. as if everything in
-            // the fragmentation context lived in one tall single column). Convert it to a
-            // visual point now.
-            LayoutPoint pointInContainer = point + offset;
-            offset += o->columnOffset(pointInContainer);
-            if (offsetDependsOnPoint)
-                *offsetDependsOnPoint = true;
-        }
-    }
-
-    if (o->hasOverflowClip())
-        offset -= toLayoutBox(o)->scrolledContentOffset();
+    LayoutSize offset = topLeftLocationOffset();
 
     if (style()->position() == AbsolutePosition && o->isRelPositioned() && o->isLayoutInline())
         offset += toLayoutInline(o)->offsetForInFlowPositionedInline(*this);
 
-    return offset;
+    return offset + LayoutBoxModelObject::offsetFromContainer(o);
 }
 
 InlineBox* LayoutBox::createInlineBox()