Use FrameTreeNode ID as frameId in extension APIs

chrome/browser/extensions/api/messaging/extension_message_port.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 CHROME_BROWSER_EXTENSIONS_API_MESSAGING_EXTENSION_MESSAGE_PORT_H_
 #define CHROME_BROWSER_EXTENSIONS_API_MESSAGING_EXTENSION_MESSAGE_PORT_H_
 
+#include "base/macros.h"
 #include "chrome/browser/extensions/api/messaging/message_service.h"
 
 class GURL;
 
 namespace content {
+class BrowserContext;
+class RenderFrameHost;
 class RenderProcessHost;
 }  // namespace content
 
+namespace IPC {
+class Message;
+}  // namespace IPC
+
 namespace extensions {
 
 // A port that manages communication with an extension.
+// The port's lifetime will end when either all receivers close the port, or
+// when the opener / receiver explicitly closes the channel.
 class ExtensionMessagePort : public MessageService::MessagePort {
  public:
-  ExtensionMessagePort(content::RenderProcessHost* process,
-                       int routing_id,
-                       const std::string& extension_id);
-  void DispatchOnConnect(int dest_port_id,
-                         const std::string& channel_name,
+  // Create a port that is tied to frame(s) in a single tab.
+  ExtensionMessagePort(base::WeakPtr<MessageService> message_service,
+                       int port_id,
+                       const std::string& extension_id,
+                       content::RenderFrameHost* rfh,
+                       bool include_child_frames);
+  // Create a port that is tied to all frames of an extension, possibly spanning
+  // multiple tabs, including the invisible background page, popups, etc.
+  ExtensionMessagePort(base::WeakPtr<MessageService> message_service,
+                       int port_id,
+                       const std::string& extension_id,
+                       content::RenderProcessHost* extension_process);
+  ~ExtensionMessagePort() override;
+
+  bool IsValidPort() override;
+
+  // MessageService::MessagePort:
+  void DispatchOnConnect(const std::string& channel_name,
                          scoped_ptr<base::DictionaryValue> source_tab,
                          int source_frame_id,
-                         int target_tab_id,
-                         int target_frame_id,
                          int guest_process_id,
                          int guest_render_frame_routing_id,
                          const std::string& source_extension_id,
                          const std::string& target_extension_id,
                          const GURL& source_url,
                          const std::string& tls_channel_id) override;
-  void DispatchOnDisconnect(int source_port_id,
-                            const std::string& error_message) override;
-  void DispatchOnMessage(const Message& message, int target_port_id) override;
+  void DispatchOnDisconnect(const std::string& error_message) override;
+  void DispatchOnMessage(const Message& message) override;
   void IncrementLazyKeepaliveCount() override;
   void DecrementLazyKeepaliveCount() override;
-  content::RenderProcessHost* GetRenderProcessHost() override;
+  void OpenPort(int process_id, int routing_id) override;
+  void ClosePort(int process_id, int routing_id) override;
 
  private:
-  content::RenderProcessHost* process_;
-  int routing_id_;
+  class FrameTracker;
+
+  // Registers a frame as a receiver / sender.
+  void RegisterFrame(content::RenderFrameHost* rfh);
+
+  // Unregisters a frame as a receiver / sender. When there are no registered
+  // frames any more, the port closes via CloseChannel().
+  void UnregisterFrame(content::RenderFrameHost* rfh);
+
+  // Immediately close the port and its associated channel.
+  void CloseChannel();
+
+  // Send a IPC message to the renderer for all registered frames.
+  void SendToPort(scoped_ptr<IPC::Message> msg);
+
+  base::WeakPtr<MessageService> weak_message_service_;
+
+  int port_id_;
   std::string extension_id_;
-  void* background_host_ptr_;  // used in IncrementLazyKeepaliveCount
+  content::BrowserContext* browser_context_;
+  // Only for receivers in an extension process.
+  content::RenderProcessHost* extension_process_;
+
+  // When the port is used as a sender, this set contains only one element.
+  // If used as a receiver, it may contain any number of frames.
+  std::set<content::RenderFrameHost*> frames_;
+
+  // Whether the renderer acknowledged creation of the port. This is used to
+  // distinguish abnormal port closure (e.g. no receivers) from explicit port
+  // closure (e.g. by the port.disconnect() JavaScript method in the renderer).
+  bool did_create_port_;
+
+  ExtensionHost* background_host_ptr_;  // used in IncrementLazyKeepaliveCount
+  scoped_ptr<FrameTracker> frame_tracker_;
+
+  DISALLOW_COPY_AND_ASSIGN(ExtensionMessagePort);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_MESSAGING_EXTENSION_MESSAGE_PORT_H_