Implements hanging property for text-indent from CSS3

Source/core/rendering/line/BreakingContextInlineHeaders.h

 /*
  * Copyright (C) 2000 Lars Knoll (knoll@kde.org)
  * Copyright (C) 2003, 2004, 2006, 2007, 2008, 2009, 2010, 2011 Apple Inc. All right reserved.
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2013 Adobe Systems Incorporated.
  *
  * 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 881 matching lines @@
         m_lastObject = m_current.object();
         if (m_lastObject->isReplaced() && m_autoWrap && (!m_lastObject->isImage() || m_allowImagesToBreak) && (!m_lastObject->isListMarker() || toRenderListMarker(m_lastObject)->isInside())) {
             m_width.commit();
             m_lineBreak.moveToStartOf(m_nextObject);
         }
     }
 }
 
 inline IndentTextOrNot requiresIndent(bool isFirstLine, bool isAfterHardLineBreak, RenderStyle* style)
 {
-    if (isFirstLine)
-        return IndentText;
-    if (isAfterHardLineBreak && style->textIndentLine() == TextIndentEachLine)
-        return IndentText;
+    IndentTextOrNot shouldIndentText = DoNotIndentText;
+    if (isFirstLine || (isAfterHardLineBreak && style->textIndentLine()) == TextIndentEachLine)
+        shouldIndentText = IndentText;
 
-    return DoNotIndentText;
+    if (style->textIndentType() == TextIndentHanging)
+        shouldIndentText = shouldIndentText == IndentText ? DoNotIndentText : IndentText;
+
+    return shouldIndentText;
 }
 
 }
 
 #endif // BreakingContextInlineHeaders_h