Add a nbsp at the the end of the text when the next text has a leading space.

third_party/WebKit/Source/core/editing/commands/CompositeEditCommand.cpp

 /*
  * Copyright (C) 2005, 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 852 matching lines @@
 
   String string = text.substring(upstream, length);
   // FIXME: Because of the problem mentioned at the top of this function, we
   // must also use nbsps at the start/end of the string because this function
   // doesn't get all surrounding whitespace, just the whitespace in the
   // current text node. However, if the next sibling node is a text node
   // (not empty, see http://crbug.com/632300), we should use a plain space.
   // See http://crbug.com/310149
   const bool nextSiblingIsTextNode =
       textNode->nextSibling() && textNode->nextSibling()->isTextNode() &&
-      toText(textNode->nextSibling())->data().length();
+      toText(textNode->nextSibling())->data().length() &&
+      toText(textNode->nextSibling())->data()[0] != ' ';
   const bool shouldEmitNBSPbeforeEnd =
       (isEndOfParagraphDeprecated(visibleDownstreamPos) ||
        (unsigned)downstream == text.length()) &&
       !nextSiblingIsTextNode;
   String rebalancedString = stringWithRebalancedWhitespace(
       string, isStartOfParagraphDeprecated(visibleUpstreamPos) || !upstream,
       shouldEmitNBSPbeforeEnd);
 
   if (string != rebalancedString)
     replaceTextInNodePreservingMarkers(textNode, upstream, length,
@@ skipping 1111 matching lines @@
   return node;
 }
 
 DEFINE_TRACE(CompositeEditCommand) {
   visitor->trace(m_commands);
   visitor->trace(m_composition);
   EditCommand::trace(visitor);
 }
 
 }  // namespace blink