Implement <appview> based on out-of-process iframes GuestView.

extensions/renderer/dispatcher.cc

 // 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 "extensions/renderer/dispatcher.h"
 
 #include <stddef.h>
 
 #include <utility>
 
@@ skipping 1564 matching lines @@
   Feature::Context context_type = context->context_type();
   ModuleSystem* module_system = context->module_system();
 
   // Only set if |context| is capable of running guests in OOPIF. Used to
   // require additional module overrides.
   bool guest_view_required = false;
 
   // Require AppView.
   if (context->GetAvailability("appViewEmbedderInternal").is_available()) {
     module_system->Require("appView");
+
+    guest_view_required = true;
   }
 
   // Require ExtensionOptions.
   if (context->GetAvailability("extensionOptionsInternal").is_available()) {
     module_system->Require("extensionOptions");
     module_system->Require("extensionOptionsAttributes");
 
     guest_view_required = true;
   }
 
@@ skipping 26 matching lines @@
   // The "guestViewDeny" module must always be loaded last. It registers
   // error-providing custom elements for the GuestView types that are not
   // available, and thus all of those types must have been checked and loaded
   // (or not loaded) beforehand.
   if (context_type == Feature::BLESSED_EXTENSION_CONTEXT) {
     module_system->Require("guestViewDeny");
   }
 }
 
 }  // namespace extensions