DCHECK that GuestViewDetachRequest receives GuestViewMsg_GuestDetached IPC.

components/guest_view/renderer/guest_view_request.cc

Index: components/guest_view/renderer/guest_view_request.cc
diff --git a/components/guest_view/renderer/guest_view_request.cc b/components/guest_view/renderer/guest_view_request.cc
index bf7ea55f131274b15088df9ff8046e30ad62c9d8..1d26c3f4462bab8457123d1ec9e911feff15fd7f 100644
--- a/components/guest_view/renderer/guest_view_request.cc
+++ b/components/guest_view/renderer/guest_view_request.cc
@@ -128,6 +128,7 @@ void GuestViewDetachRequest::PerformRequest() {
 }
 
 void GuestViewDetachRequest::HandleResponse(const IPC::Message& message) {
+  DCHECK(message.type() == GuestViewMsg_GuestDetached::ID);
   ExecuteCallbackIfAvailable(0 /* argc */, nullptr);
 }