No longer store page logical height in LayoutState.

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

 /*
  * Copyright (C) 2012 Apple 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:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 468 matching lines @@
   return columnSet;
 }
 
 void LayoutMultiColumnFlowThread::layoutColumns(
     SubtreeLayoutScope& layoutScope) {
   // Since we ended up here, it means that the multicol container (our parent)
   // needed layout. Since contents of the multicol container are diverted to the
   // flow thread, the flow thread needs layout as well.
   layoutScope.setChildNeedsLayout(this);
 
+  calculateColumnHeightAvailable();
+
   if (FragmentationContext* enclosingFragmentationContext =
           this->enclosingFragmentationContext()) {
     m_blockOffsetInEnclosingFragmentationContext =
         multiColumnBlockFlow()->offsetFromLogicalTopOfFirstPage();
     m_blockOffsetInEnclosingFragmentationContext +=
         multiColumnBlockFlow()->borderAndPaddingBefore();
 
     if (LayoutMultiColumnFlowThread* enclosingFlowThread =
             enclosingFragmentationContext->associatedFlowThread()) {
       if (LayoutMultiColumnSet* firstSet = firstMultiColumnSet()) {
@@ skipping 150 matching lines @@
     LayoutUnit blockOffset) {
   return pageLogicalHeightForOffset(blockOffset);
 }
 
 LayoutUnit LayoutMultiColumnFlowThread::remainingLogicalHeightAt(
     LayoutUnit blockOffset) {
   return pageRemainingLogicalHeightForOffset(blockOffset,
                                              AssociateWithLatterPage);
 }
 
+void LayoutMultiColumnFlowThread::calculateColumnHeightAvailable() {
+  // Calculate the non-auto content box height, or set it to 0 if it's auto. We
+  // need to know this before layout, so that we can figure out where to insert
+  // column breaks. We also treat LayoutView (which may be paginated, which uses
+  // the multicol implementation) as having a fixed height, since its height is
+  // deduced from the viewport height. We use computeLogicalHeight() to
+  // calculate the content box height. That method will clamp against max-height
+  // and min-height. Since we're now at the beginning of layout, and we don't
+  // know the actual height of the content yet, only call that method when
+  // height is definite, or we might fool ourselves into believing that columns
+  // have a definite height when they in fact don't.
+  LayoutBlockFlow* container = multiColumnBlockFlow();
+  LayoutUnit columnHeight;
+  if (container->hasDefiniteLogicalHeight() || container->isLayoutView()) {
+    LogicalExtentComputedValues computedValues;
+    container->computeLogicalHeight(LayoutUnit(), container->logicalTop(),
+                                    computedValues);
+    columnHeight = computedValues.m_extent -
+                   container->borderAndPaddingLogicalHeight() -
+                   container->scrollbarLogicalHeight();
+  }
+  setColumnHeightAvailable(std::max(columnHeight, LayoutUnit()));
+}
+
 void LayoutMultiColumnFlowThread::calculateColumnCountAndWidth(
     LayoutUnit& width,
     unsigned& count) const {
   LayoutBlock* columnBlock = multiColumnBlockFlow();
   const ComputedStyle* columnStyle = columnBlock->style();
   LayoutUnit availableWidth = columnBlock->contentLogicalWidth();
   LayoutUnit columnGap = LayoutUnit(columnBlock->columnGap());
   LayoutUnit computedColumnWidth =
       max(LayoutUnit(1), LayoutUnit(columnStyle->columnWidth()));
   unsigned computedColumnCount = max<int>(1, columnStyle->columnCount());
@@ skipping 651 matching lines @@
     const {
   return MultiColumnLayoutState(m_lastSetWorkedOn);
 }
 
 void LayoutMultiColumnFlowThread::restoreMultiColumnLayoutState(
     const MultiColumnLayoutState& state) {
   m_lastSetWorkedOn = state.columnSet();
 }
 
 }  // namespace blink