Make <webview> use out-of-process iframe architecture.

extensions/renderer/guest_view/extensions_guest_view_container.h

 // 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.
 
 #ifndef EXTENSIONS_RENDERER_GUEST_VIEW_EXTENSIONS_GUEST_VIEW_CONTAINER_H_
 #define EXTENSIONS_RENDERER_GUEST_VIEW_EXTENSIONS_GUEST_VIEW_CONTAINER_H_
 
 #include <queue>
 
 #include "components/guest_view/renderer/guest_view_container.h"
 #include "v8/include/v8.h"
 
 namespace gfx {
 class Size;
 }
 
 namespace extensions {
 
 class ExtensionsGuestViewContainer : public guest_view::GuestViewContainer {
  public:
   explicit ExtensionsGuestViewContainer(content::RenderFrame* render_frame);
 
-  void RegisterDestructionCallback(v8::Local<v8::Function> callback,
-                                   v8::Isolate* isolate);
   void RegisterElementResizeCallback(v8::Local<v8::Function> callback,
                                      v8::Isolate* isolate);
 
   // BrowserPluginDelegate implementation.
   void DidResizeElement(const gfx::Size& new_size) override;
 
  protected:
   ~ExtensionsGuestViewContainer() override;
 
  private:
   void CallElementResizeCallback(const gfx::Size& new_size);
 
   // GuestViewContainer implementation.
   void OnDestroy(bool embedder_frame_destroyed) override;
 
-  v8::Global<v8::Function> destruction_callback_;
-  v8::Isolate* destruction_isolate_;
-
   v8::Global<v8::Function> element_resize_callback_;
   v8::Isolate* element_resize_isolate_;
 
   // Weak pointer factory used for calling the element resize callback.
   base::WeakPtrFactory<ExtensionsGuestViewContainer> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionsGuestViewContainer);
 };
 
 }  // namespace extensions
 
 #endif  // EXTENSIONS_RENDERER_GUEST_VIEW_EXTENSIONS_GUEST_VIEW_CONTAINER_H_