The rest of the Presentation API IDL as stubs.

Source/modules/presentation/PresentationSession.h

Index: Source/modules/presentation/PresentationSession.h
diff --git a/Source/modules/presentation/Presentation.h b/Source/modules/presentation/PresentationSession.h
similarity index 50%
copy from Source/modules/presentation/Presentation.h
copy to Source/modules/presentation/PresentationSession.h
index be2cdae35e86df34e2d8c50bf7aa4be53934a949..728e61614d3b9670b5e95ad6403ab7292a06d473 100644
--- a/Source/modules/presentation/Presentation.h
+++ b/Source/modules/presentation/PresentationSession.h
@@ -2,24 +2,25 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef Presentation_h
-#define Presentation_h
+#ifndef PresentationSession_h
+#define PresentationSession_h
 
 #include "core/dom/ContextLifecycleObserver.h"
 #include "core/events/EventTarget.h"
+#include "wtf/text/WTFString.h"
 
 namespace blink {
 
-class Presentation final
-    : public RefCountedGarbageCollectedWillBeGarbageCollectedFinalized<Presentation>
+class PresentationSession final
+    : public RefCountedGarbageCollectedWillBeGarbageCollectedFinalized<PresentationSession>
     , public EventTargetWithInlineData
     , public ContextLifecycleObserver {
-    DEFINE_EVENT_TARGET_REFCOUNTING_WILL_BE_REMOVED(RefCountedGarbageCollected<Presentation>);
-    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(Presentation);
+    DEFINE_EVENT_TARGET_REFCOUNTING_WILL_BE_REMOVED(RefCountedGarbageCollected<PresentationSession>);
+    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(PresentationSession);
     DEFINE_WRAPPERTYPEINFO();
 public:
-    static Presentation* create(ExecutionContext*);
-    virtual ~Presentation();
+    static PresentationSession* create(ExecutionContext*);
+    virtual ~PresentationSession();
 
     // EventTarget implementation.
     virtual const AtomicString& interfaceName() const override;
@@ -27,12 +28,22 @@ public:
 
     virtual void trace(Visitor*) override;
 
-    DEFINE_ATTRIBUTE_EVENT_LISTENER(availablechange);
+    const String& id() const { return m_id; }
+    const AtomicString& state() const { return m_state; }
+
+    void postMessage(const String& message);
+    void close();
+
+    DEFINE_ATTRIBUTE_EVENT_LISTENER(message);
+    DEFINE_ATTRIBUTE_EVENT_LISTENER(statechange);
 
 private:
-    explicit Presentation(ExecutionContext*);
+    explicit PresentationSession(ExecutionContext*);
+
+    String m_id;
+    AtomicString m_state;
 };
 
 } // namespace blink
 
-#endif // Presentation_h
+#endif // PresentationSession_h