collapseMargins   569 Source/core/rendering/RenderBlockFlow.cpp     LayoutUnit logicalTopBeforeClear = collapseMargins(child, marginInfo, childIsSelfCollapsing);
collapseMargins   427 Source/core/rendering/RenderBlockFlow.h     LayoutUnit collapseMargins(RenderBox* child, MarginInfo&, bool childIsSelfCollapsing);