Clear mutable inline style when it is empty.

Source/core/editing/RemoveCSSPropertyCommand.cpp

 /*
  * Copyright (C) 2005, 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 32 matching lines @@
     ASSERT(m_element);
 }
 
 RemoveCSSPropertyCommand::~RemoveCSSPropertyCommand()
 {
 }
 
 void RemoveCSSPropertyCommand::doApply()
 {
     const StylePropertySet* style = m_element->inlineStyle();
+    if (!style) {

[eseidel, 2013/12/23 21:22:43]

Although (I think?) we allow {} around one-line ifs these days, historically
they were verbotten and most places in blink still avoid them.

[chrishtr, 2013/12/23 22:06:46]

Done.

+        return;
+    }
+
     m_oldValue = style->getPropertyValue(m_property);
     m_important = style->propertyIsImportant(m_property);
 
     // Mutate using the CSSOM wrapper so we get the same event behavior as a script.
     // Setting to null string removes the property. We don't have internal version of removeProperty.
     m_element->style()->setPropertyInternal(m_property, String(), false, IGNORE_EXCEPTION);
 }
 
 void RemoveCSSPropertyCommand::doUnapply()
 {
     m_element->style()->setPropertyInternal(m_property, m_oldValue, m_important, IGNORE_EXCEPTION);
 }
 
 } // namespace WebCore