Add iterator support to FontFaceSet

Source/core/css/FontFaceSet.h

Index: Source/core/css/FontFaceSet.h
diff --git a/Source/core/css/FontFaceSet.h b/Source/core/css/FontFaceSet.h
index 6a334872573e8352e4eb8dcb5990a4c14c69fd03..c3cea021e7457d127ad90620a9812c387479e2a7 100644
--- a/Source/core/css/FontFaceSet.h
+++ b/Source/core/css/FontFaceSet.h
@@ -30,6 +30,7 @@
 #include "core/css/FontFace.h"
 #include "core/css/FontFaceSetForEachCallback.h"
 #include "core/dom/ActiveDOMObject.h"
+#include "core/dom/Iterator.h"
 #include "core/events/EventListener.h"
 #include "core/events/EventTarget.h"
 #include "platform/AsyncMethodRunner.h"
@@ -84,10 +85,16 @@ public:
     void forEach(PassOwnPtrWillBeRawPtr<FontFaceSetForEachCallback>, const ScriptValue& thisArg) const;
     void forEach(PassOwnPtrWillBeRawPtr<FontFaceSetForEachCallback>) const;
     bool has(FontFace*, ExceptionState&) const;
+    Iterator* keys();
+    Iterator* values();
+    Iterator* entries();
+    Iterator* iterator(ScriptState*, ExceptionState&) { return values(); }
 
     unsigned long size() const;
     AtomicString status() const;
 
+    FontFace* fontFaceAt(size_t index) const;
+
     virtual ExecutionContext* executionContext() const OVERRIDE;
     virtual const AtomicString& interfaceName() const OVERRIDE;
 
@@ -113,6 +120,33 @@ public:
 #endif
 
 private:
+    class FontFaceSetIterator FINAL : public Iterator {
+    public:
+        enum Kind { Keys, Values, Entries };
+
+        FontFaceSetIterator(PassRefPtrWillBeRawPtr<FontFaceSet> fontFaceSet, Kind kind)
+            : m_fontFaceSet(fontFaceSet)
+            , m_kind(kind)
+            , m_index(0) { }
+        virtual ~FontFaceSetIterator() { }
+        virtual ScriptValue next(ScriptState*, ExceptionState&) OVERRIDE;
+        virtual ScriptValue next(ScriptState* scriptState, ScriptValue, ExceptionState& exceptionState) OVERRIDE
+        {
+            return next(scriptState, exceptionState);
+        }
+
+        virtual void trace(Visitor* visitor) OVERRIDE
+        {
+            visitor->trace(m_fontFaceSet);
+            Iterator::trace(visitor);
+        }
+
+    private:
+        RefPtrWillBeMember<FontFaceSet> m_fontFaceSet;
+        Kind m_kind;
+        size_t m_index;
+    };
+
     static PassRefPtrWillBeRawPtr<FontFaceSet> create(Document& document)
     {
         return adoptRefWillBeNoop(new FontFaceSet(document));