[Presentation API] PresentationRequest::getAvailability() should return the same promise

third_party/WebKit/Source/modules/presentation/PresentationPromiseProperty.h

Index: third_party/WebKit/Source/modules/presentation/PresentationPromiseProperty.h
diff --git a/third_party/WebKit/Source/modules/presentation/PresentationPromiseProperty.h b/third_party/WebKit/Source/modules/presentation/PresentationPromiseProperty.h
new file mode 100644
index 0000000000000000000000000000000000000000..0b507a9494057e6733a69d7b13c050ffbb27fdb6
--- /dev/null
+++ b/third_party/WebKit/Source/modules/presentation/PresentationPromiseProperty.h
@@ -0,0 +1,23 @@
+// Copyright 2016 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 PresentationPromiseProperty_h
+#define PresentationPromiseProperty_h
+
+#include "bindings/core/v8/ScriptPromiseProperty.h"
+#include "core/dom/DOMException.h"
+
+namespace blink {
+
+class PresentationAvailability;
+class PresentationRequest;
+
+using PresentationAvailabilityProperty =
+    ScriptPromiseProperty<Member<PresentationRequest>,
+                          Member<PresentationAvailability>,
+                          Member<DOMException>>;
+
+}  // namespace blink
+
+#endif  // PresentationPromiseProperty_h