Add the Presentation API module and a single event target

Source/modules/presentation/NavigatorPresentation.cpp

Index: Source/modules/presentation/NavigatorPresentation.cpp
diff --git a/Source/modules/presentation/NavigatorPresentation.cpp b/Source/modules/presentation/NavigatorPresentation.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..6b5437217ba1db3db5fc34c006435c5b11924a23
--- /dev/null
+++ b/Source/modules/presentation/NavigatorPresentation.cpp
@@ -0,0 +1,65 @@
+// 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) {
+        if (!frame())
+            return 0;

[Peter Beverloo, 2014/09/12 15:07:23]

Out of interest, when would this be a valid case? Should we ASSERT instead?

[whywhat, 2014/09/12 15:17:43]

Hm, in comment #8 Eric asked "won't it fail it frame() is null" so I believed it
is possible :)

+        m_presentation = Presentation::create(frame()->document());
+    }
+    return m_presentation.get();
+}
+
+void NavigatorPresentation::trace(Visitor* visitor)
+{
+    visitor->trace(m_presentation);
+    WillBeHeapSupplement<Navigator>::trace(visitor);
+    DOMWindowProperty::trace(visitor);
+}
+
+} // namespace blink