Presentation API: Blink changes to allow getAvailability() to be rejected.

Source/modules/presentation/PresentationError.h

 // 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.
 
 #ifndef PresentationError_h
 #define PresentationError_h
 
 #include "platform/heap/Handle.h"
 #include "public/platform/modules/presentation/WebPresentationError.h"
 
 namespace blink {
 
 class DOMException;
 
 // A container of methods taking care of WebPresentationError in WebCallbacks subclasses.
 class PresentationError final {
     WTF_MAKE_NONCOPYABLE(PresentationError);
 public:
-    static DOMException* take(WebPresentationError*);
-    static void dispose(WebPresentationError*);
+    static DOMException* take(const WebPresentationError&);
 
 private:
+    PresentationError() = delete;
     ~PresentationError() = delete;
 };
 
 } // namespace blink
 
 #endif // PresentationError_h