[Typed OM] Remove MutableStylePropertyMap - it seems unnecessary.

third_party/WebKit/Source/core/css/cssom/InlineStylePropertyMap.h

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef InlineStylePropertyMap_h
 #define InlineStylePropertyMap_h
 
-#include "core/css/cssom/MutableStylePropertyMap.h"
+#include "core/css/cssom/StylePropertyMap.h"
 #include "core/dom/Element.h"
 
 namespace blink {
 
-class CORE_EXPORT InlineStylePropertyMap final
-    : public MutableStylePropertyMap {
+class CORE_EXPORT InlineStylePropertyMap final : public StylePropertyMap {
   WTF_MAKE_NONCOPYABLE(InlineStylePropertyMap);
 
  public:
   explicit InlineStylePropertyMap(Element* ownerElement)
       : m_ownerElement(ownerElement) {}
 
   Vector<String> getProperties() override;
 
   void set(CSSPropertyID,
            CSSStyleValueOrCSSStyleValueSequenceOrString&,
            ExceptionState&) override;
   void append(CSSPropertyID,
               CSSStyleValueOrCSSStyleValueSequenceOrString&,
               ExceptionState&) override;
   void remove(CSSPropertyID, ExceptionState&) override;
 
   DEFINE_INLINE_VIRTUAL_TRACE() {
     visitor->trace(m_ownerElement);
-    MutableStylePropertyMap::trace(visitor);
+    StylePropertyMap::trace(visitor);
   }
 
  protected:
   CSSStyleValueVector getAllInternal(CSSPropertyID) override;
   CSSStyleValueVector getAllInternal(AtomicString customPropertyName) override;
 
   HeapVector<StylePropertyMapEntry> getIterationEntries() override;
 
  private:
   Member<Element> m_ownerElement;
 };
 
 }  // namespace blink
 
 #endif