Add the Presentation API module and a single event target

Source/modules/presentation/NavigatorPresentation.cpp

+// 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.
+
+#include "config.h"
+#include "modules/presentation/NavigatorPresentation.h"
+
+#include "core/dom/Document.h"
+#include "core/frame/LocalFrame.h"
+#include "core/frame/Navigator.h"
+#include "modules/presentation/Presentation.h"
+#include "platform/heap/Handle.h"
+
+namespace blink {
+
+NavigatorPresentation::NavigatorPresentation(LocalFrame* frame)
+    : DOMWindowProperty(frame)
+{
+}
+
+NavigatorPresentation::~NavigatorPresentation()
+{
+}
+
+// static
+const char* NavigatorPresentation::supplementName()
+{
+    return "NavigatorPresentation";
+}
+
+// static
+NavigatorPresentation& NavigatorPresentation::from(Navigator& navigator)
+{
+    NavigatorPresentation* supplement = static_cast<NavigatorPresentation*>(WillBeHeapSupplement<Navigator>::from(navigator, supplementName()));
+    if (!supplement) {
+        supplement = new NavigatorPresentation(navigator.frame());
+        provideTo(navigator, supplementName(), adoptPtrWillBeNoop(supplement));
+    }
+    return *supplement;
+}
+
+// static
+Presentation& NavigatorPresentation::presentation(Navigator& navigator)
+{
+    return NavigatorPresentation::from(navigator).presentation();
+}
+
+Presentation& NavigatorPresentation::presentation()
+{
+    if (!m_presentation && frame())
+        m_presentation = Presentation::create(frame()->document());
+    return *m_presentation.get();

[eseidel, 2014/08/19 18:20:58]

Won't this fail if frame is null?

[whywhat, 2014/08/20 16:40:42]

Should I then change the return type to a pointer and return null?

+}
+
+void NavigatorPresentation::trace(Visitor* visitor)
+{
+    visitor->trace(m_presentation);
+    WillBeHeapSupplement<Navigator>::trace(visitor);
+}
+
+} // namespace blink