[PresentationAPI] Plumbing |onstatechange| event for the PresentationSession from Blink to platform/

Source/modules/presentation/PresentationSession.h

 // Copyright 2014 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 PresentationSession_h
 #define PresentationSession_h
 
 #include "core/events/EventTarget.h"
 #include "core/frame/DOMWindowProperty.h"
+#include "public/platform/WebString.h"
+#include "public/platform/modules/presentation/WebPresentationSessionClient.h"

[mlamouri (slow - plz ping), 2015/03/23 17:54:16]

With enum class for the enum, you can forward declare it with |enum class
SessionState;|

[whywhat, 2015/03/23 21:12:16]

I'll try that but if I have to pass the enum by reference I probably won't
accept the suggestion.

 #include "wtf/text/AtomicString.h"
-#include "wtf/text/WTFString.h"
 
 namespace blink {
 
 class Presentation;
 class PresentationController;
-class WebPresentationSessionClient;
-class WebString;
 
 class PresentationSession final
     : public RefCountedGarbageCollectedEventTargetWithInlineData<PresentationSession>
     , public DOMWindowProperty {
     DEFINE_EVENT_TARGET_REFCOUNTING_WILL_BE_REMOVED(RefCountedGarbageCollected<PresentationSession>);
     WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(PresentationSession);
     DEFINE_WRAPPERTYPEINFO();
 public:
     static PresentationSession* take(WebPresentationSessionClient*, Presentation*);
     static void dispose(WebPresentationSessionClient*);
     virtual ~PresentationSession();
 
     // EventTarget implementation.
     virtual const AtomicString& interfaceName() const override;
     virtual ExecutionContext* executionContext() const override;
 
     DECLARE_VIRTUAL_TRACE();
 
-    const String& id() const { return m_id; }
-    const AtomicString& state() const { return m_state; }
+    const String id() const { return m_id; }
+    const AtomicString state() const;
 
     void postMessage(const String& message);
     void close();
 
     DEFINE_ATTRIBUTE_EVENT_LISTENER(message);
     DEFINE_ATTRIBUTE_EVENT_LISTENER(statechange);
 
+    // Returns true if and only if the WebPresentationSessionClient represents this session.

[Peter Beverloo, 2015/03/20 19:07:40]

"matches" sounds like something that could be a pattern. Why not call this
isEqual?

nit: could use "iff" instead of "if and only if".

[mlamouri (slow - plz ping), 2015/03/23 17:54:16]

A PresentationSession being equal to a PresentationSessionClient sounds odd to
me. Matches is fine as far as I am concerned.

+    bool matches(WebPresentationSessionClient*) const;
+
+    // Notifies the session about its state change.
+    void didChangeState(WebPresentationSessionClient::SessionState);
+
 private:
     PresentationSession(LocalFrame*, const WebString& id, const WebString& url);
 
     // Returns the |PresentationController| object associated with the frame
     // |Presentation| corresponds to. Can return |nullptr| if the frame is
     // detached from the document.
     PresentationController* presentationController();
 
-    String m_id;
-    String m_url;
-    AtomicString m_state;
+    WebString m_id;
+    WebString m_url;
+    WebPresentationSessionClient::SessionState m_state;
 };
 
 } // namespace blink
 
 #endif // PresentationSession_h