Don't eat margins when column height isn't yet known.

Source/core/layout/LayoutBlockFlow.cpp

Index: Source/core/layout/LayoutBlockFlow.cpp
diff --git a/Source/core/layout/LayoutBlockFlow.cpp b/Source/core/layout/LayoutBlockFlow.cpp
index d5aa6480168454a965083e47349e587897ca1998..01ab7038773e0ec0bc5541ad2ac6054d82546cd0 100644
--- a/Source/core/layout/LayoutBlockFlow.cpp
+++ b/Source/core/layout/LayoutBlockFlow.cpp
@@ -1311,7 +1311,7 @@ LayoutUnit LayoutBlockFlow::collapseMargins(LayoutBox& child, MarginInfo& margin
     // If margins would pull us past the top of the next page, then we need to pull back and pretend like the margins
     // collapsed into the page edge.
     LayoutState* layoutState = view()->layoutState();
-    if (layoutState->isPaginated() && layoutState->pageLogicalHeight() && logicalTop > beforeCollapseLogicalTop) {
+    if (layoutState->isPaginated() && isPageLogicalHeightKnown(beforeCollapseLogicalTop) && logicalTop > beforeCollapseLogicalTop) {
         LayoutUnit oldLogicalTop = logicalTop;
         logicalTop = std::min(logicalTop, nextPageLogicalTop(beforeCollapseLogicalTop));
         setLogicalHeight(logicalHeight() + (logicalTop - oldLogicalTop));
@@ -1532,7 +1532,7 @@ LayoutUnit LayoutBlockFlow::estimateLogicalTopPosition(LayoutBox& child, const M
     // Adjust logicalTopEstimate down to the next page if the margins are so large that we don't fit on the current
     // page.
     LayoutState* layoutState = view()->layoutState();
-    if (layoutState->isPaginated() && layoutState->pageLogicalHeight() && logicalTopEstimate > logicalHeight())
+    if (layoutState->isPaginated() && isPageLogicalHeightKnown(logicalHeight()) && logicalTopEstimate > logicalHeight())
         logicalTopEstimate = std::min(logicalTopEstimate, nextPageLogicalTop(logicalHeight()));
 
     logicalTopEstimate += getClearDelta(&child, logicalTopEstimate);