Fix LayoutUnit snapping of widths in line breaker

third_party/WebKit/Source/core/layout/line/LineWidth.h

 /*
  * Copyright (C) 2013 Adobe Systems Incorporated. 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.
@@ skipping 69 matching lines @@
   void shrinkAvailableWidthForNewFloatIfNeeded(const FloatingObject&);
   void addUncommittedWidth(float delta) { m_uncommittedWidth += delta; }
   void commit();
   void applyOverhang(LineLayoutRubyRun,
                      LineLayoutItem startLayoutItem,
                      LineLayoutItem endLayoutItem);
   void fitBelowFloats(bool isFirstLine = false);
   void setTrailingWhitespaceWidth(float width) {
     m_trailingWhitespaceWidth = width;
   }
-  void snapUncommittedWidth() {
-    m_uncommittedWidth =
-        LayoutUnit::fromFloatCeil(m_uncommittedWidth).toFloat();
+  void snapAtNodeBoundary() {
+    if (!m_uncommittedWidth) {
+      m_committedWidth = LayoutUnit::fromFloatCeil(m_committedWidth).toFloat();
+    } else {
+      m_uncommittedWidth =
+          LayoutUnit::fromFloatCeil(m_committedWidth + m_uncommittedWidth)
+              .toFloat() -
+          m_committedWidth;
+    }
   }
 
   IndentTextOrNot indentText() const { return m_indentText; }
 
  private:
   void computeAvailableWidthFromLeftAndRight();
   void updateLineDimension(LayoutUnit newLineTop,
                            LayoutUnit newLineWidth,
                            const LayoutUnit& newLineLeft,
                            const LayoutUnit& newLineRight);
   void wrapNextToShapeOutside(bool isFirstLine);
 
   LineLayoutBlockFlow m_block;
   float m_uncommittedWidth;
   float m_committedWidth;
   // The amount by which |m_availableWidth| has been inflated to account for
   // possible contraction due to ruby overhang.
   float m_overhangWidth;
   float m_trailingWhitespaceWidth;
   LayoutUnit m_left;
   LayoutUnit m_right;
   LayoutUnit m_availableWidth;
   bool m_isFirstLine;
   IndentTextOrNot m_indentText;
 };
 
 }  // namespace blink
 
 #endif  // LineWidth_h