Remove port lifetime management from renderer

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"
 
@@ skipping 23 matching lines @@
                        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;
 
+  // Check whether the port exists in the frames. Frames that don't know about

[Devlin, 2016/05/17 19:50:29]

nitty nit: descriptive rather than imperative function comments, so this should
be "Checks"

[Devlin, 2016/05/17 19:50:29]

Specify "the frames"

[robwu, 2016/05/17 22:47:50]

Done 2x.

+  // the port are removed from the set of frames. This should be used for opener
+  // ports because the frame may be navigated before the port was initialized.
+  void RevalidatePort();
+
   // MessageService::MessagePort:
   void RemoveCommonFrames(const MessagePort& port) override;
   bool HasFrame(content::RenderFrameHost* rfh) const override;
   bool IsValidPort() override;
   void DispatchOnConnect(const std::string& channel_name,
                          std::unique_ptr<base::DictionaryValue> source_tab,
                          int source_frame_id,
                          int guest_process_id,
                          int guest_render_frame_routing_id,
                          const std::string& source_extension_id,
@@ skipping 31 matching lines @@
   // 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.
   // This set is populated before the first message is sent to the destination,
   // and shrinks over time when the port is rejected by the recipient frame, or
   // when the frame is removed or unloaded.
   std::set<content::RenderFrameHost*> frames_;
 
+  // The ID of the tab where the channel was created. This is saved so that any
+  // onMessage events can be run in the scope of the tab.
+  // Only set on receiver ports (if the opener was a tab).

[Devlin, 2016/05/17 19:50:29]

Specify that this is -1 if invalid (pretty common, but good to be explicit)

[robwu, 2016/05/17 22:47:50]

Done.

+  int opener_tab_id_;
+
   // 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
   std::unique_ptr<FrameTracker> frame_tracker_;
 
   DISALLOW_COPY_AND_ASSIGN(ExtensionMessagePort);
 };
 
 }  // namespace extensions
 
 #endif  // CHROME_BROWSER_EXTENSIONS_API_MESSAGING_EXTENSION_MESSAGE_PORT_H_