Clear mutable inline style when it is empty.

Source/core/css/InlineVariablesIterator.h

Index: Source/core/css/InlineVariablesIterator.h
diff --git a/Source/core/svg/SVGMissingGlyphElement.h b/Source/core/css/InlineVariablesIterator.h
similarity index 60%
copy from Source/core/svg/SVGMissingGlyphElement.h
copy to Source/core/css/InlineVariablesIterator.h
index 9057582fab5b7327dca133aafb31cd9db8a70a56..532079560a3ea8d6f8265b40edfa4c0c4f78cdb7 100644
--- a/Source/core/svg/SVGMissingGlyphElement.h
+++ b/Source/core/css/InlineVariablesIterator.h
@@ -1,5 +1,5 @@
 /*
- * Copyright (C) 2007 Eric Seidel <eric@webkit.org>
+ * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ -17,28 +17,27 @@
  * Boston, MA 02110-1301, USA.
  */
 
-#ifndef SVGMissingGlyphElement_h
-#define SVGMissingGlyphElement_h
+#ifndef InlineVariablesIterator_h
+#define InlineVariablesIterator_h
 
-#if ENABLE(SVG_FONTS)
-#include "SVGNames.h"
-#include "core/svg/SVGElement.h"
+#include "core/css/VariablesIterator.h"
 
 namespace WebCore {
 
-class SVGMissingGlyphElement FINAL : public SVGElement {
+class Element;
+
+// A CSSVariablesIterator implementation for the inline style of an element.
+class InlineVariablesIterator : public AbstractVariablesIterator {
 public:
-    static PassRefPtr<SVGMissingGlyphElement> create(Document&);
+    static PassRefPtr<InlineVariablesIterator> create(Element*);
 
 private:
-    explicit SVGMissingGlyphElement(Document&);
+    explicit InlineVariablesIterator(Element*);
+    virtual MutableStylePropertySet* propertySet() const OVERRIDE;
 
-    virtual bool rendererIsNeeded(const RenderStyle&) { return false; }
+    RefPtr<Element> m_element;
 };
 
-DEFINE_NODE_TYPE_CASTS(SVGMissingGlyphElement, hasTagName(SVGNames::missing_glyphTag));
-
 } // namespace WebCore
 
-#endif // ENABLE(SVG_FONTS)
-#endif
+#endif // InlineVariablesIterator_h