[DevTools] Rework DevToolsSession interaction with domain handlers.

content/browser/devtools/devtools_agent_host_impl.h

 // 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.
 
 #ifndef CONTENT_BROWSER_DEVTOOLS_DEVTOOLS_AGENT_HOST_IMPL_H_
 #define CONTENT_BROWSER_DEVTOOLS_DEVTOOLS_AGENT_HOST_IMPL_H_
 
 #include <stdint.h>
 
 #include <string>
 
 #include "base/compiler_specific.h"
 #include "content/browser/devtools/devtools_io_context.h"
 #include "content/common/content_export.h"
 #include "content/common/devtools_messages.h"
 #include "content/public/browser/devtools_agent_host.h"
 
 namespace content {
 
 class BrowserContext;
 class DevToolsSession;
 
 // Describes interface for managing devtools agents from the browser process.
 class CONTENT_EXPORT DevToolsAgentHostImpl : public DevToolsAgentHost {
  public:
-  // Informs the hosted agent that a client host has attached.
-  virtual void Attach() = 0;
-
-  // Informs the hosted agent that a client host has detached.
-  virtual void Detach() = 0;
-
   // DevToolsAgentHost implementation.
   bool AttachClient(DevToolsAgentHostClient* client) override;
   void ForceAttachClient(DevToolsAgentHostClient* client) override;
   bool DetachClient(DevToolsAgentHostClient* client) override;
   bool DispatchProtocolMessage(DevToolsAgentHostClient* client,
                                const std::string& message) override;
   bool IsAttached() override;
   void InspectElement(DevToolsAgentHostClient* client, int x, int y) override;
   std::string GetId() override;
   std::string GetParentId() override;
   std::string GetDescription() override;
   GURL GetFaviconURL() override;
   std::string GetFrontendURL() override;
   base::TimeTicks GetLastActivityTime() override;
   BrowserContext* GetBrowserContext() override;
   WebContents* GetWebContents() override;
   void DisconnectWebContents() override;
   void ConnectWebContents(WebContents* wc) override;
 
   bool Inspect();
   void SendMessageToClient(int session_id, const std::string& message);
 
  protected:
   DevToolsAgentHostImpl(const std::string& id);
   ~DevToolsAgentHostImpl() override;
 
   static bool ShouldForceCreation();
 
-  virtual bool DispatchProtocolMessage(const std::string& message) = 0;
-  virtual void InspectElement(int x, int y);
+  virtual void AttachSession(DevToolsSession* session) = 0;
+  virtual void DetachSession(int session_id) = 0;
+  virtual bool DispatchProtocolMessage(
+      DevToolsSession* session,
+      const std::string& message) = 0;
+  virtual void InspectElement(DevToolsSession* session, int x, int y);
 
   void NotifyCreated();
-  void HostClosed();
+  void ForceDetach(bool replaced);
   DevToolsIOContext* GetIOContext() { return &io_context_; }
 
+  // TODO(dgozman): remove this accessor.
   DevToolsSession* session() { return session_.get(); }
 
  private:
   friend class DevToolsAgentHost; // for static methods
-  bool InnerAttach(DevToolsAgentHostClient* client, bool force);
-  void InnerDetach();
+  bool InnerAttachClient(DevToolsAgentHostClient* client, bool force);
+  void InnerDetachClient();
   void NotifyAttached();
   void NotifyDetached();
   void NotifyDestroyed();
 
   const std::string id_;
-  int session_id_;
   int last_session_id_;
   std::unique_ptr<DevToolsSession> session_;
-  DevToolsAgentHostClient* client_;
   DevToolsIOContext io_context_;
   static int s_attached_count_;
   static int s_force_creation_count_;
 };
 
 class DevToolsMessageChunkProcessor {
  public:
   using SendMessageCallback = base::Callback<void(int, const std::string&)>;
   explicit DevToolsMessageChunkProcessor(const SendMessageCallback& callback);
   ~DevToolsMessageChunkProcessor();
 
   std::string state_cookie() const { return state_cookie_; }
   void set_state_cookie(const std::string& cookie) { state_cookie_ = cookie; }
   int last_call_id() const { return last_call_id_; }
   bool ProcessChunkedMessageFromAgent(const DevToolsMessageChunk& chunk);
 
  private:
   SendMessageCallback callback_;
   std::string message_buffer_;
   uint32_t message_buffer_size_;
   std::string state_cookie_;
   int last_call_id_;
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_DEVTOOLS_DEVTOOLS_AGENT_HOST_IMPL_H_