[DevTools] Dedicated frontend for debugging Node.

content/browser/devtools/protocol/target_handler.cc

 // Copyright 2016 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 "content/browser/devtools/protocol/target_handler.h"
 
 #include "content/browser/devtools/devtools_manager.h"
 #include "content/browser/devtools/devtools_session.h"
 #include "content/browser/devtools/service_worker_devtools_agent_host.h"
 #include "content/browser/frame_host/frame_tree.h"
@@ skipping 394 matching lines @@
   attached_hosts_.erase(host->GetId());
 }
 
 // -------------- DevToolsAgentHostObserver -----------------
 
 bool TargetHandler::ShouldForceDevToolsAgentHostCreation() {
   return true;
 }
 
 void TargetHandler::DevToolsAgentHostCreated(DevToolsAgentHost* agent_host) {
-  DCHECK(attached_hosts_.find(agent_host->GetId()) == attached_hosts_.end());
+  // If we start discovering late, all existing agent hosts will be reported,
+  // but we could have already attached to some.
   TargetCreatedInternal(agent_host);
 }
 
 void TargetHandler::DevToolsAgentHostDestroyed(DevToolsAgentHost* agent_host) {
   DCHECK(attached_hosts_.find(agent_host->GetId()) == attached_hosts_.end());
   TargetDestroyedInternal(agent_host);
 }
 
 // -------- ServiceWorkerDevToolsManager::Observer ----------
 
@@ skipping 30 matching lines @@
   UpdateServiceWorkers();
 }
 
 void TargetHandler::WorkerDestroyed(
     ServiceWorkerDevToolsAgentHost* host) {
   UpdateServiceWorkers();
 }
 
 }  // namespace protocol
 }  // namespace content