Fix wrong cast in ExtensionsGuestViewContainer.

extensions/renderer/guest_view/guest_view_internal_custom_bindings.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/guest_view/guest_view_internal_custom_bindings.h"
 
 #include <string>
 #include <utility>
 
 #include "base/bind.h"
@@ skipping 232 matching lines @@
   DCHECK(parent_frame->isWebLocalFrame());
 
   content::RenderFrame* embedder_parent_frame =
       content::RenderFrame::FromWebFrame(parent_frame);
 
   // Create a GuestViewContainer if it does not exist.
   // An element instance ID uniquely identifies an IframeGuestViewContainer
   // within a RenderView.
   auto* guest_view_container =
       static_cast<guest_view::IframeGuestViewContainer*>(
           guest_view::GuestViewContainer::FromID(element_instance_id));

[meacer, 2016/10/18 19:41:53]

Can you also remove this cast? It's not really necessary.

[lfg, 2016/10/19 19:18:40]

Done.

   // This is the first time we hear about the |element_instance_id|.
   DCHECK(!guest_view_container);
   // The <webview> element's GC takes ownership of |guest_view_container|.
   guest_view_container =
       new guest_view::IframeGuestViewContainer(embedder_parent_frame);
   guest_view_container->SetElementInstanceID(element_instance_id);
 
   std::unique_ptr<guest_view::GuestViewRequest> request(
       new guest_view::GuestViewAttachIframeRequest(
           guest_view_container, render_frame->GetRoutingID(), guest_instance_id,
@@ skipping 111 matching lines @@
   // There are two parameters.
   CHECK(args.Length() == 2);
   // Element Instance ID.
   CHECK(args[0]->IsInt32());
   // Callback function.
   CHECK(args[1]->IsFunction());
 
   int element_instance_id = args[0]->Int32Value();
   // An element instance ID uniquely identifies a ExtensionsGuestViewContainer
   // within a RenderView.
-  auto* guest_view_container = static_cast<ExtensionsGuestViewContainer*>(
-      guest_view::GuestViewContainer::FromID(element_instance_id));
+  auto* guest_view_container =
+      guest_view::GuestViewContainer::FromID(element_instance_id);
   if (!guest_view_container)
     return;
 
   guest_view_container->RegisterElementResizeCallback(
       args[1].As<v8::Function>(), args.GetIsolate());
 
   args.GetReturnValue().Set(v8::Boolean::New(context()->isolate(), true));
 }
 
 void GuestViewInternalCustomBindings::RegisterView(
@@ skipping 32 matching lines @@
     const v8::FunctionCallbackInfo<v8::Value>& args) {
   // Gesture is required to request fullscreen.
   blink::WebScopedUserGesture user_gesture;
   CHECK_EQ(args.Length(), 1);
   CHECK(args[0]->IsFunction());
   v8::Local<v8::Value> no_args;
   context()->CallFunction(v8::Local<v8::Function>::Cast(args[0]), 0, &no_args);
 }
 
 }  // namespace extensions