Clear mutable inline style when it is empty.

Source/core/editing/ApplyStyleCommand.cpp

 /*
  * Copyright (C) 2005, 2006, 2008, 2009 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 939 matching lines @@
         return style->conflictsWithInlineStyleOfElement(element);
 
     Vector<CSSPropertyID> properties;
     if (!style->conflictsWithInlineStyleOfElement(element, extractedStyle, properties))
         return false;
 
     // FIXME: We should use a mass-removal function here but we don't have an undoable one yet.
     for (size_t i = 0; i < properties.size(); i++)
         removeCSSProperty(element, properties[i]);
 
-    // No need to serialize <foo style=""> if we just removed the last css property
-    if (element->inlineStyle()->isEmpty())
-        removeNodeAttribute(element, styleAttr);
-
     if (isSpanWithoutAttributesOrUnstyledStyleSpan(element))
         removeNodePreservingChildren(element);
 
     return true;
 }
 
 HTMLElement* ApplyStyleCommand::highestAncestorWithConflictingInlineStyle(EditingStyle* style, Node* node)
 {
     if (!node)
         return 0;
@@ skipping 573 matching lines @@
         String textToMove = nextText->data();
         insertTextIntoNode(childText, childText->length(), textToMove);
         removeNode(next);
         // don't move child node pointer. it may want to merge with more text nodes.
     }
 
     updateStartEnd(newStart, newEnd);
 }
 
 }