Be more restrictive about forcing relayout of children for pagination.

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

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 437 matching lines @@
   LayoutAnalyzer::BlockScope analyzer(*this);
   SubtreeLayoutScope layoutScope(*this);
 
   // Multiple passes might be required for column based layout.
   // The number of passes could be as high as the number of columns.
   bool done = false;
   LayoutUnit pageLogicalHeight;
   while (!done)
     done = layoutBlockFlow(relayoutChildren, pageLogicalHeight, layoutScope);
 
-  LayoutView* layoutView = view();
-  if (layoutView->layoutState()->pageLogicalHeight())
-    setPageLogicalOffset(
-        layoutView->layoutState()->pageLogicalOffset(*this, logicalTop()));
-
   updateLayerTransformAfterLayout();
 
   updateAfterLayout();
 
   if (isHTMLDialogElement(node()) && isOutOfFlowPositioned())
     positionDialog();
 
   clearNeedsLayout();
   updateIsSelfCollapsing();
 }
@@ skipping 300 matching lines @@
     if (newLogicalTop != oldLogicalTop && child.shrinkToAvoidFloats()) {
       // The child's width is affected by adjacent floats. When the child shifts
       // to clear an item, its width can change (because it has more available
       // width).
       layoutScope.setChildNeedsLayout(&child);
     } else {
       markChildForPaginationRelayoutIfNeeded(child, layoutScope);
     }
   }
 
-  if (!child.needsLayout())
-    return false;
-  child.layout();
-  return true;
+  bool neededLayout = child.needsLayout();
+  if (neededLayout)
+    child.layout();
+  if (view()->layoutState()->isPaginated())
+    updateFragmentationInfoForChild(child);
+  return neededLayout;
 }
 
 void LayoutBlockFlow::insertForcedBreakBeforeChildIfNeeded(
     LayoutBox& child,
     BlockChildrenLayoutInfo& layoutInfo) {
   if (layoutInfo.isAtFirstInFlowChild()) {
     // There's no class A break point before the first child (only *between*
     // siblings), so steal its break value and join it with what we already have
     // here.
     setBreakBefore(
@@ skipping 3758 matching lines @@
   return LayoutBlock::invalidatePaintIfNeeded(paintInvalidationState);
 }
 
 void LayoutBlockFlow::invalidateDisplayItemClients(
     PaintInvalidationReason invalidationReason) const {
   BlockFlowPaintInvalidator(*this).invalidateDisplayItemClients(
       invalidationReason);
 }
 
 }  // namespace blink