Implement iterable<DOMString, (StyleValue or sequence<StyleValue>)> for InlineStylePropertyMap

third_party/WebKit/Source/core/css/cssom/StylePropertyMap.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 StylePropertyMap_h
 #define StylePropertyMap_h
 
 #include "bindings/core/v8/Iterable.h"
 #include "bindings/core/v8/ScriptWrappable.h"
 #include "bindings/core/v8/UnionTypesCore.h"
 #include "core/CSSPropertyNames.h"
 #include "core/CoreExport.h"
 #include "core/css/cssom/StyleValue.h"
 
 namespace blink {
 
 class ExceptionState;
 
 class CORE_EXPORT StylePropertyMap : public GarbageCollectedFinalized<StylePropertyMap>, public ScriptWrappable, public PairIterable<String, StyleValueOrStyleValueSequence> {
     WTF_MAKE_NONCOPYABLE(StylePropertyMap);
     DEFINE_WRAPPERTYPEINFO();
 public:
     typedef HeapVector<Member<StyleValue>> StyleValueVector;
+    typedef std::pair<String, StyleValueOrStyleValueSequence> StylePropertyMapEntry;
 
     virtual ~StylePropertyMap() { }
 
     // Accessors.
     StyleValue* get(const String& propertyName, ExceptionState&);
     StyleValueVector getAll(const String& propertyName, ExceptionState&);
     bool has(const String& propertyName, ExceptionState&);
 
     virtual StyleValueVector getAll(CSSPropertyID) = 0;
     virtual bool has(CSSPropertyID) = 0;
 
     virtual Vector<String> getProperties() = 0;
 
     // Modifiers.
     void set(const String& propertyName, StyleValueOrStyleValueSequenceOrString& item, ExceptionState&);
     void append(const String& propertyName, StyleValueOrStyleValueSequenceOrString& item, ExceptionState&);
     void remove(const String& propertyName, ExceptionState&);
 
     virtual void set(CSSPropertyID, StyleValueOrStyleValueSequenceOrString& item, ExceptionState&) = 0;
     virtual void append(CSSPropertyID, StyleValueOrStyleValueSequenceOrString& item, ExceptionState&) = 0;
     virtual void remove(CSSPropertyID, ExceptionState&) = 0;
 
     DEFINE_INLINE_VIRTUAL_TRACE() { }
 
 protected:
     StylePropertyMap() { }
 
-    IterationSource* startIteration(ScriptState*, ExceptionState&) override { return nullptr; }
+    virtual HeapVector<StylePropertyMapEntry> getIterationEntries() = 0;
+    IterationSource* startIteration(ScriptState*, ExceptionState&) override;
     StyleValueVector cssValueToStyleValueVector(CSSPropertyID, const CSSValue&);
 };
 
 } // namespace blink
 
 #endif