text-justify fix for Chinese and Japanese

Source/platform/fonts/shaping/SimpleShaper.cpp

 /*
  * Copyright (C) 2003, 2006, 2008, 2009, 2010, 2011 Apple Inc. All rights reserved.
  * Copyright (C) 2008 Holger Hans Peter Freyther
  * Copyright (C) 2014 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
  * License as published by the Free Software Foundation; either
  * version 2 of the License, or (at your option) any later version.
  *
@@ skipping 87 matching lines @@
     m_fallbackFonts->add(fontData);
 }
 
 float SimpleShaper::adjustSpacing(float width, const CharacterData& charData)
 {
     // Account for letter-spacing.
     if (width)
         width += m_font->fontDescription().letterSpacing();
 
     bool isExpansionOpportunity = Character::treatAsSpace(charData.character) || (m_run.textJustify() == TextJustifyDistribute);
-    if (isExpansionOpportunity) {
+    if (isExpansionOpportunity || (m_run.textJustify() == TextJustifyAuto && Character::isCJKIdeographOrSymbol(charData.character))) {
         // Distribute the run's total expansion evenly over all expansion opportunities in the run.
         if (m_expansion) {
             if (!isExpansionOpportunity && !m_isAfterExpansion) {
                 // Take the expansion opportunity before this ideograph.
                 m_expansion -= m_expansionPerOpportunity;
                 m_runWidthSoFar += m_expansionPerOpportunity;
             }
             if (m_run.allowsTrailingExpansion()
                 || (m_run.ltr() && charData.characterOffset + charData.clusterLength < static_cast<size_t>(m_run.length()))
                 || (m_run.rtl() && charData.characterOffset)) {
@@ skipping 123 matching lines @@
     float initialWidth = m_runWidthSoFar;
 
     if (!advance(m_currentCharacter + 1))
         return false;
 
     width = m_runWidthSoFar - initialWidth;
     return true;
 }
 
 } // namespace blink