Add 'exposed' objects and embeds to a document's named properties.

Source/core/html/HTMLEmbedElement.h

Index: Source/core/html/HTMLEmbedElement.h
diff --git a/Source/core/html/HTMLEmbedElement.h b/Source/core/html/HTMLEmbedElement.h
index 06a1ef44c883ddde443ac7b94644b6633aa0d8ba..83009fbda0789e7bbcbe6adc2c3d4d7e08210560 100644
--- a/Source/core/html/HTMLEmbedElement.h
+++ b/Source/core/html/HTMLEmbedElement.h
@@ -31,6 +31,8 @@ class HTMLEmbedElement FINAL : public HTMLPlugInElement {
 public:
     static PassRefPtr<HTMLEmbedElement> create(Document&, bool createdByParser = false);
 
+    bool isExposed() const;
+
 private:
     HTMLEmbedElement(Document&, bool createdByParser);
 
@@ -55,6 +57,8 @@ private:
     virtual bool isInteractiveContent() const OVERRIDE;
 };
 
+DEFINE_NODE_TYPE_CASTS(HTMLEmbedElement, hasTagName(HTMLNames::embedTag));
+
 }
 
 #endif