[Experimental] Implement some part of custom properties in style maps

third_party/WebKit/Source/core/css/cssom/ComputedStylePropertyMap.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 ComputedStylePropertyMap_h
 #define ComputedStylePropertyMap_h
 
 #include "core/css/CSSComputedStyleDeclaration.h"
 #include "core/css/cssom/ImmutableStylePropertyMap.h"
 #include "core/dom/Node.h"
@@ skipping 14 matching lines @@
 
  public:
   static ComputedStylePropertyMap* create(Node* node,
                                           const String& pseudoElement) {
     return new ComputedStylePropertyMap(node, pseudoElement);
   }
 
   Vector<String> getProperties() override;
 
   DEFINE_INLINE_VIRTUAL_TRACE() {
-    visitor->trace(m_computedStyleDeclaration);
     visitor->trace(m_node);
     ImmutableStylePropertyMap::trace(visitor);
   }
 
  private:
   Node* node() const;
 
  protected:
   ComputedStylePropertyMap(Node* node, const String& pseudoElement = String())
       : ImmutableStylePropertyMap(),
-        m_computedStyleDeclaration(
-            CSSComputedStyleDeclaration::create(node, false, pseudoElement)),
         m_pseudoId(CSSSelector::parsePseudoId(pseudoElement)),
         m_node(node) {}
 
   CSSStyleValueVector getAllInternal(CSSPropertyID) override;
-  CSSStyleValueVector getAllInternal(AtomicString customPropertyName) override;
+  CSSStyleValueVector getAllInternal(String customPropertyName) override;
 
   HeapVector<StylePropertyMapEntry> getIterationEntries() override {
     return HeapVector<StylePropertyMapEntry>();
   }
 
-  Member<CSSComputedStyleDeclaration> m_computedStyleDeclaration;
   PseudoId m_pseudoId;

[meade_UTC10, 2017/03/02 00:16:59]

I think these members should be private; if you move the private Node* function
above to just above the members, that would be perfect.

   Member<Node> m_node;
 };
 
 }  // namespace blink
 
 #endif