Make leadingWhitespacePosition() to respect "white-space" CSS property

third_party/WebKit/Source/core/editing/EditingUtilities.cpp

 /*
  * Copyright (C) 2004, 2005, 2006, 2007 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 1384 matching lines @@
         return Position();
 
     const Position& prev = previousCharacterPosition(position, affinity);
     if (prev == position)
         return Position();
     const Node* const anchorNode = prev.anchorNode();
     if (!anchorNode || !anchorNode->isTextNode())
         return Position();
     if (enclosingBlockFlowElement(*anchorNode) != enclosingBlockFlowElement(*position.anchorNode()))
         return Position();
-    if (!anchorNode->isTextNode())
+    if (option == NotConsiderNonCollapsibleWhitespace && anchorNode->layoutObject() && !anchorNode->layoutObject()->style()->collapseWhiteSpace())
         return Position();
     const String& string = toText(anchorNode)->data();
     const UChar previousCharacter = string[prev.computeOffsetInContainerNode()];
     const bool isSpace = option == ConsiderNonCollapsibleWhitespace ? (isSpaceOrNewline(previousCharacter) || previousCharacter == noBreakSpaceCharacter) : isCollapsibleWhitespace(previousCharacter);
     if (!isSpace || !isEditablePosition(prev))
         return Position();
     return prev;
 }
 
 // This assumes that it starts in editable content.
@@ skipping 284 matching lines @@
     // instead of possibly at the end of the last node before the selection
     return mostForwardCaretPosition(visiblePosition.deepEquivalent());
 }
 
 bool isTextSecurityNode(const Node* node)
 {
     return node && node->layoutObject() && node->layoutObject()->style()->textSecurity() != TSNONE;
 }
 
 } // namespace blink