[DevTools] Support multiple sessions in Target domain

content/browser/devtools/protocol/target_handler.h

 // 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.
 
 #ifndef CONTENT_BROWSER_DEVTOOLS_PROTOCOL_TARGET_HANDLER_H_
 #define CONTENT_BROWSER_DEVTOOLS_PROTOCOL_TARGET_HANDLER_H_
 
 #include <map>
 #include <set>
 
 #include "content/browser/devtools/protocol/devtools_domain_handler.h"
 #include "content/browser/devtools/protocol/target.h"
 #include "content/browser/devtools/service_worker_devtools_manager.h"
-#include "content/public/browser/devtools_agent_host_client.h"
 #include "content/public/browser/devtools_agent_host_observer.h"
 
 namespace content {
 
 class DevToolsAgentHostImpl;
 class RenderFrameHostImpl;
 
 namespace protocol {
 
 class TargetHandler : public DevToolsDomainHandler,
                       public Target::Backend,
-                      public DevToolsAgentHostClient,
                       public ServiceWorkerDevToolsManager::Observer,
                       public DevToolsAgentHostObserver {
  public:
   TargetHandler();
   ~TargetHandler() override;
 
   static std::vector<TargetHandler*> ForAgentHost(DevToolsAgentHostImpl* host);
 
   void Wire(UberDispatcher* dispatcher) override;
   void SetRenderFrameHost(RenderFrameHostImpl* host) override;
   Response Disable() override;
 
   void UpdateServiceWorkers();
   void UpdateFrames();
 
   // Domain implementation.
   Response SetDiscoverTargets(bool discover) override;
   Response SetAutoAttach(bool auto_attach,
                          bool wait_for_debugger_on_start) override;
   Response SetAttachToFrames(bool value) override;
   Response SetRemoteLocations(
       std::unique_ptr<protocol::Array<Target::RemoteLocation>>) override;
   Response AttachToTarget(const std::string& target_id,
-                          bool* out_success) override;
-  Response DetachFromTarget(const std::string& target_id) override;
-  Response SendMessageToTarget(const std::string& target_id,
+                          Maybe<std::string>* out_session_id) override;
+  Response DetachFromTarget(const std::string& session_id) override;
+  Response SendMessageToTarget(const std::string& session_id,
                                const std::string& message) override;
   Response GetTargetInfo(
       const std::string& target_id,
       std::unique_ptr<Target::TargetInfo>* target_info) override;
   Response ActivateTarget(const std::string& target_id) override;
   Response CloseTarget(const std::string& target_id,
                        bool* out_success) override;
   Response CreateBrowserContext(std::string* out_context_id) override;
   Response DisposeBrowserContext(const std::string& context_id,
                                  bool* out_success) override;
   Response CreateTarget(const std::string& url,
                         Maybe<int> width,
                         Maybe<int> height,
                         Maybe<std::string> context_id,
                         std::string* out_target_id) override;
   Response GetTargets(
       std::unique_ptr<protocol::Array<Target::TargetInfo>>* target_infos)
       override;
 
  private:
   using HostsMap = std::map<std::string, scoped_refptr<DevToolsAgentHost>>;
   using RawHostsMap = std::map<std::string, DevToolsAgentHost*>;
 
   void UpdateServiceWorkers(bool waiting_for_debugger);
   void ReattachTargetsOfType(const HostsMap& new_hosts,
                              const std::string& type,
                              bool waiting_for_debugger);
   void TargetCreatedInternal(DevToolsAgentHost* host);
   void TargetDestroyedInternal(DevToolsAgentHost* host);
-  bool AttachToTargetInternal(DevToolsAgentHost* host,
-                              bool waiting_for_debugger);
-  void DetachFromTargetInternal(DevToolsAgentHost* host);
+  std::string AttachToTargetInternal(DevToolsAgentHost* host,
+                                     bool waiting_for_debugger,
+                                     bool is_auto_attach);
+  bool DetachFromSessionInternal(const std::string& session_id);
+  bool IsAttachedToAgentHost(DevToolsAgentHost* agent_host);
 
   // ServiceWorkerDevToolsManager::Observer implementation.
   void WorkerCreated(ServiceWorkerDevToolsAgentHost* host) override;
   void WorkerReadyForInspection(ServiceWorkerDevToolsAgentHost* host) override;
   void WorkerVersionInstalled(ServiceWorkerDevToolsAgentHost* host) override;
   void WorkerVersionDoomed(ServiceWorkerDevToolsAgentHost* host) override;
   void WorkerDestroyed(ServiceWorkerDevToolsAgentHost* host) override;
 
   // DevToolsAgentHostObserver implementation.
   bool ShouldForceDevToolsAgentHostCreation() override;
   void DevToolsAgentHostCreated(DevToolsAgentHost* agent_host) override;
   void DevToolsAgentHostDestroyed(DevToolsAgentHost* agent_host) override;
   void DevToolsAgentHostAttached(DevToolsAgentHost* agent_host) override;
   void DevToolsAgentHostDetached(DevToolsAgentHost* agent_host) override;
 
-  // DevToolsAgentHostClient implementation.
-  void DispatchProtocolMessage(DevToolsAgentHost* agent_host,
-                               const std::string& message) override;
-  void AgentHostClosed(DevToolsAgentHost* agent_host,
-                       bool replaced_with_another_client) override;
+  class Session;
 
   std::unique_ptr<Target::Frontend> frontend_;
   bool discover_;
   bool auto_attach_;
   bool wait_for_debugger_on_start_;
   bool attach_to_frames_;
   RenderFrameHostImpl* render_frame_host_;
-  HostsMap attached_hosts_;
+  std::map<std::string, std::unique_ptr<Session>> attached_sessions_;
+  HostsMap auto_attached_hosts_;

[caseq, 2017/06/27 18:29:30]

Does this have to be a map -- i.e. can it be a set<DevToolsAgentHost> instead?

   std::set<GURL> frame_urls_;
   RawHostsMap reported_hosts_;
+  int last_session_id_ = 0;
 
   DISALLOW_COPY_AND_ASSIGN(TargetHandler);
 };
 
 }  // namespace protocol
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_DEVTOOLS_PROTOCOL_TARGET_HANDLER_H_