Bug 1586468 Part 2 - Use observer service to listen for content process connects/disconnects, r=ochameau.

Depends on D48260

Differential Revision: https://phabricator.services.mozilla.com/D48262

--HG--
extra : moz-landing-system : lando

devtools/server/actors/process.js

@@ -4,7 +4,8 @@
 
 "use strict";
 
-var { Cc } = require("chrome");
+const { Cc } = require("chrome");
+const Services = require("Services");
 
 loader.lazyGetter(this, "ppmm", () => {
   return Cc["@mozilla.org/parentprocessmessagemanager;1"].getService();
@@ -14,10 +15,7 @@ function ProcessActorList() {
   this._actors = new Map();
   this._onListChanged = null;
   this._mustNotify = false;
-
-  this._onMessage = this._onMessage.bind(this);
-  this._processScript =
-    "resource://devtools/server/startup/debug-new-process.js";
+  this._hasObserver = false;
 }
 
 ProcessActorList.prototype = {
@@ -58,31 +56,24 @@ ProcessActorList.prototype = {
 
   _checkListening: function() {
     if (this._onListChanged !== null && this._mustNotify) {
-      this._knownProcesses = [];
-      for (let i = 0; i < ppmm.childCount; i++) {
-        this._knownProcesses.push(ppmm.getChildAt(i));
+      if (!this._hasObserver) {
+        Services.obs.addObserver(this, "ipc:content-created");
+        Services.obs.addObserver(this, "ipc:content-shutdown");
+        this._hasObserver = true;
       }
-      ppmm.addMessageListener("debug:new-process", this._onMessage);
-      ppmm.loadProcessScript(this._processScript, true);
-    } else {
-      ppmm.removeMessageListener("debug:new-process", this._onMessage);
-      ppmm.removeDelayedProcessScript(this._processScript);
+    } else if (this._hasObserver) {
+      Services.obs.removeObserver(this, "ipc:content-created");
+      Services.obs.removeObserver(this, "ipc:content-shutdown");
+      this._hasObserver = false;
     }
   },
 
-  _notifyListChanged: function() {
+  observe() {
     if (this._mustNotify) {
       this._onListChanged();
       this._mustNotify = false;
     }
   },
-
-  _onMessage: function({ target }) {
-    if (this._knownProcesses.includes(target)) {
-      return;
-    }
-    this._notifyListChanged();
-  },
 };
 
 exports.ProcessActorList = ProcessActorList;

devtools/server/startup/debug-new-process.js

@@ -1,9 +0,0 @@
-/* This Source Code Form is subject to the terms of the Mozilla Public
- * License, v. 2.0. If a copy of the MPL was not distributed with this
- * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
-
-"use strict";
-
-/* global sendAsyncMessage */
-
-sendAsyncMessage("debug:new-process");

devtools/server/startup/moz.build

@@ -7,7 +7,6 @@
 DevToolsModules(
     'content-process.js',
     'content-process.jsm',
-    'debug-new-process.js',
     'frame.js',
     'worker.js',
 )