[Presentation API] OffscreenPresentationManager should only interact with top level receiver frame

content/browser/presentation/presentation_service_impl.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 CONTENT_BROWSER_PRESENTATION_PRESENTATION_SERVICE_IMPL_H_
 #define CONTENT_BROWSER_PRESENTATION_PRESENTATION_SERVICE_IMPL_H_
 
 #include <deque>
 #include <map>
 #include <memory>
@@ skipping 260 matching lines @@
       pending_reconnect_presentation_cbs_;
 
   // RAII binding of |this| to an Presentation interface request.
   // The binding is removed when binding_ is cleared or goes out of scope.
   std::unique_ptr<mojo::Binding<blink::mojom::PresentationService>> binding_;
 
   // ID of the RenderFrameHost this object is associated with.
   int render_process_id_;
   int render_frame_id_;
 
+  // If current frame is top level frame.
+  bool is_main_frame_;
+
   // NOTE: Weak pointers must be invalidated before all other member variables.
   base::WeakPtrFactory<PresentationServiceImpl> weak_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(PresentationServiceImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_PRESENTATION_PRESENTATION_SERVICE_IMPL_H_