[PresentationAPI] Added plumbing for start/joinSession from JS to platform

Source/modules/presentation/PresentationSessionClientCallbacks.cpp

+// Copyright 2015 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.
+
+#include "config.h"
+#include "modules/presentation/PresentationSessionClientCallbacks.h"
+
+#include "bindings/core/v8/ScriptPromiseResolver.h"
+#include "core/dom/DOMException.h"
+#include "core/dom/ExceptionCode.h"
+#include "modules/presentation/Presentation.h"
+#include "modules/presentation/PresentationSession.h"
+#include "public/platform/WebString.h"
+#include "public/platform/modules/presentation/WebPresentationError.h"
+
+namespace blink {
+
+PresentationSessionClientCallbacks::PresentationSessionClientCallbacks(
+    PassRefPtrWillBeRawPtr<ScriptPromiseResolver> resolver,
+    Presentation* presentation)
+    : m_resolver(resolver)
+    , m_presentation(presentation)
+{
+    ASSERT(m_resolver);
+    ASSERT(m_presentation);
+}
+
+PresentationSessionClientCallbacks::~PresentationSessionClientCallbacks()
+{
+}
+
+// |session| takes ownership of |client| and |m_presentation| takes ownership of the session.
+void PresentationSessionClientCallbacks::onSuccess(WebPresentationSessionClient* client)
+{
+    ASSERT(client);
+    PresentationSession* session = PresentationSession::create(m_presentation->frame(), client);

[mlamouri (slow - plz ping), 2015/02/25 20:51:06]

Could you rewrite that so it follows the same pattern as CallbackPromiseAdapter.
It would imply having a ::take() method instead of ::create().

There are a few checks on m_resolver that you are not doing and should be doing.

[whywhat, 2015/02/25 22:46:52]

I added the checks and fixed ownership of the parameters passed. I think my code
is simpler and clearer that what you suggested about following
CallbackPromiseAdapter though equivalent.

+    m_presentation->didCreateSession(session);
+    m_resolver->resolve(session);
+}
+
+void PresentationSessionClientCallbacks::onError(WebPresentationError* error)
+{
+    ASSERT(error);
+    // TODO(avayvod): figure out the mapping between WebPresentationError and
+    // DOMException error codes.
+    m_resolver->reject(DOMException::create(InvalidAccessError, error->message));

[mlamouri (slow - plz ping), 2015/02/25 20:51:06]

ditto.

[whywhat, 2015/02/25 22:46:52]

Done.

+
+    delete error;
+}
+
+} // namespace blink