Correct inline-block baseline calculation for multicol containers.

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 327 matching lines @@
     LayoutUnit blockOffset = isHorizontalWritingMode() ? visualPoint.y() : visualPoint.x();
     const LayoutMultiColumnSet* columnSet = nullptr;
     for (const LayoutMultiColumnSet* candidate = firstMultiColumnSet(); candidate; candidate = candidate->nextSiblingMultiColumnSet()) {
         columnSet = candidate;
         if (candidate->logicalBottom() > blockOffset)
             break;
     }
     return columnSet ? columnSet->visualPointToFlowThreadPoint(toLayoutPoint(visualPoint + location() - columnSet->location())) : visualPoint;
 }
 
+int LayoutMultiColumnFlowThread::inlineBlockBaseline(LineDirectionMode lineDirection) const
+{
+    LayoutUnit baselineInFlowThread = LayoutUnit(LayoutFlowThread::inlineBlockBaseline(lineDirection));
+    LayoutMultiColumnSet* columnSet = columnSetAtBlockOffset(baselineInFlowThread);
+    if (!columnSet)
+        return baselineInFlowThread.toInt();
+    return (baselineInFlowThread - columnSet->pageLogicalTopForOffset(baselineInFlowThread)).ceil();
+}
+
 LayoutMultiColumnSet* LayoutMultiColumnFlowThread::columnSetAtBlockOffset(LayoutUnit offset) const
 {
     if (LayoutMultiColumnSet* columnSet = m_lastSetWorkedOn) {
         // Layout in progress. We are calculating the set heights as we speak, so the column set range
         // information is not up-to-date.
         while (columnSet->logicalTopInFlowThread() > offset) {
             // Sometimes we have to use a previous set. This happens when we're working with a block
             // that contains a spanner (so that there's a column set both before and after the
             // spanner, and both sets contain said block).
             LayoutMultiColumnSet* previousSet = columnSet->previousSiblingMultiColumnSet();
@@ skipping 647 matching lines @@
         }
         if (canContainSpannerInParentFragmentationContext(*object))
             next = object->nextInPreOrder(&root);
         else
             next = object->nextInPreOrderAfterChildren(&root);
     }
     return true;
 }
 
 } // namespace blink