[CSS Typed OM] Rearrange StylePropertyMap classes to match the new spec.

third_party/WebKit/Source/core/css/cssom/ImmutableStylePropertyMap.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 ImmutableStylePropertyMap_h
-#define ImmutableStylePropertyMap_h
-
-#include "core/css/cssom/StylePropertyMap.h"
-
-namespace blink {
-
-class CORE_EXPORT ImmutableStylePropertyMap : public StylePropertyMap {
-  WTF_MAKE_NONCOPYABLE(ImmutableStylePropertyMap);
-
- public:
-  void set(CSSPropertyID,
-           CSSStyleValueOrCSSStyleValueSequenceOrString&,
-           ExceptionState& exceptionState) override {
-    exceptionState.throwTypeError("This StylePropertyMap is immutable.");
-  }
-
-  void append(CSSPropertyID,
-              CSSStyleValueOrCSSStyleValueSequenceOrString&,
-              ExceptionState& exceptionState) override {
-    exceptionState.throwTypeError("This StylePropertyMap is immutable.");
-  }
-
-  void remove(CSSPropertyID, ExceptionState& exceptionState) override {
-    exceptionState.throwTypeError("This StylePropertyMap is immutable.");
-  }
-
- protected:
-  ImmutableStylePropertyMap() = default;
-};
-
-}  // namespace blink
-
-#endif