Use NonBreakingSpace glyph where available

Source/platform/fonts/GlyphPageTreeNode.cpp

 /*
  * Copyright (C) 2006, 2007, 2008 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
@@ skipping 147 matching lines @@
                     buffer[i] = start + i;
 
                 if (start == 0) {
                     // Control characters must not render at all.
                     for (i = 0; i < 0x20; ++i)
                         buffer[i] = zeroWidthSpace;
                     for (i = 0x7F; i < 0xA0; i++)
                         buffer[i] = zeroWidthSpace;
                     buffer[softHyphen] = zeroWidthSpace;
 
-                    // \n, \t, and nonbreaking space must render as a space.
+                    // \n and \t must render as a space.
                     buffer[newlineCharacter] = space;
                     buffer[characterTabulation] = space;
-                    buffer[noBreakSpace] = space;
                 } else if (start == (arabicLetterMark & ~(GlyphPage::size - 1))) {
                     buffer[arabicLetterMark - start] = zeroWidthSpace;
                 } else if (start == (leftToRightMark & ~(GlyphPage::size - 1))) {
                     // LRM, RLM, LRE, RLE, ZWNJ, ZWJ, and PDF must not render at all.
                     buffer[leftToRightMark - start] = zeroWidthSpace;
                     buffer[rightToLeftMark - start] = zeroWidthSpace;
                     buffer[leftToRightEmbed - start] = zeroWidthSpace;
                     buffer[rightToLeftEmbed - start] = zeroWidthSpace;
                     buffer[leftToRightOverride - start] = zeroWidthSpace;
                     buffer[rightToLeftOverride - start] = zeroWidthSpace;
@@ skipping 204 matching lines @@
     if (level > fontData->maxGlyphPageTreeLevel())
         return;
 
     GlyphPageTreeNodeMap::iterator end = m_children.end();
     for (GlyphPageTreeNodeMap::iterator it = m_children.begin(); it != end; ++it)
         it->value->pruneFontData(fontData, level);
 }
 
 } // namespace blink