Add a crash-hunting CHECK() in RenderProcessHostImpl::AddRoute()

content/browser/renderer_host/render_process_host_impl.cc

 // Copyright (c) 2012 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.
 
 // Represents the browser side of the browser <--> renderer communication
 // channel. There will be one RenderProcessHost per renderer process.
 
 #include "content/browser/renderer_host/render_process_host_impl.h"
 
 #include <algorithm>
@@ skipping 905 matching lines @@
 }
 
 ServiceRegistry* RenderProcessHostImpl::GetServiceRegistry() {
   DCHECK(mojo_application_host_);
   return mojo_application_host_->service_registry();
 }
 
 void RenderProcessHostImpl::AddRoute(
     int32 routing_id,
     IPC::Listener* listener) {
+  // We already have DCHECK() in IDMap. This is for chasing
+  // crbug.com/415059 and can be removed after fixing it.
+  CHECK(!listeners_.Lookup(routing_id));
   listeners_.AddWithID(listener, routing_id);
 }
 
 void RenderProcessHostImpl::RemoveRoute(int32 routing_id) {
   DCHECK(listeners_.Lookup(routing_id) != NULL);
   listeners_.Remove(routing_id);
 
 #if defined(OS_WIN)
   // Dump the handle table if handle auditing is enabled.
   const base::CommandLine& browser_command_line =
@@ skipping 1316 matching lines @@
   if (worker_ref_count_ == 0)
     Cleanup();
 }
 
 void RenderProcessHostImpl::EnsureMojoActivated() {
   mojo_activation_required_ = true;
   MaybeActivateMojo();
 }
 
 }  // namespace content