Remove port lifetime management from renderer

chrome/browser/extensions/api/messaging/extension_message_port.h

Index: chrome/browser/extensions/api/messaging/extension_message_port.h
diff --git a/chrome/browser/extensions/api/messaging/extension_message_port.h b/chrome/browser/extensions/api/messaging/extension_message_port.h
index dd6e584fc5ef842cd18a8e4161cb1b2950516c6e..d1dd08c2c0f808a8a6cd16707b2e1b5abc5775fb 100644
--- a/chrome/browser/extensions/api/messaging/extension_message_port.h
+++ b/chrome/browser/extensions/api/messaging/extension_message_port.h
@@ -41,6 +41,11 @@ class ExtensionMessagePort : public MessageService::MessagePort {
                        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;
@@ -92,6 +97,11 @@ class ExtensionMessagePort : public MessageService::MessagePort {
   // 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).