Bug 1689297 - [devtools] Add cloned content process message resource. r=ochameau,devtools-backward-compat-reviewers.

This is a legacy-listener-only resource that is required for us to receive the
messages cloned from the content process in the browser console when the `devtools.browsertoolbox.fission`
pref is not enabled.
Since the messages are sent through the `consoleApiCall` event, we add a `clonedFromContentProcess`
flag so we can ignore legit console api messages, which are handled as another resource.

This let us remove the specific code in WebConnectionProxy.

Differential Revision: https://phabricator.services.mozilla.com/D103284

devtools/client/webconsole/webconsole-connection-proxy.js

@@ -22,18 +22,10 @@ class WebConsoleConnectionProxy {
    *        A WebConsoleUI instance that owns this connection proxy.
    * @param {RemoteTarget} target
    *        The target that the console will connect to.
-   * @param {Boolean} needContentProcessMessagesListener
-   *        Set to true to specifically add a ContentProcessMessages listener. This is
-   *        needed for non-fission Browser Console for example.
    */
-  constructor(
+  constructor(webConsoleUI, target) {
-    webConsoleUI,
-    target,
-    needContentProcessMessagesListener = false
-  ) {
     this.webConsoleUI = webConsoleUI;
     this.target = target;
-    this.needContentProcessMessagesListener = needContentProcessMessagesListener;
     this._connecter = null;
 
     this._onTabNavigated = this._onTabNavigated.bind(this);
@@ -66,8 +58,6 @@ class WebConsoleConnectionProxy {
       this.client = this.target.client;
       this.webConsoleFront = await this.target.getFront("console");
 
-      await this._attachConsole();
-
       // There is no way to view response bodies from the Browser Console, so do
       // not waste the memory.
       const saveBodies =
@@ -109,23 +99,6 @@ class WebConsoleConnectionProxy {
     return this._connecter;
   }
 
-  /**
-   * Attach to the Web Console actor.
-   * @private
-   * @returns Promise
-   */
-  _attachConsole() {
-    if (!this.webConsoleFront || !this.needContentProcessMessagesListener) {
-      return null;
-    }
-
-    // Enable the forwarding of console messages to the parent process
-    // when we open the Browser Console or Toolbox without fission support. If Fission
-    // is enabled, we don't use the ContentProcessMessages listener, but attach to the
-    // content processes directly.
-    return this.webConsoleFront.startListeners(["ContentProcessMessages"]);
-  }
-
   /**
    * Sets all the relevant event listeners on the webconsole client.
    *

devtools/client/webconsole/webconsole-ui.js

@@ -349,6 +349,7 @@ class WebConsoleUI {
         resourceWatcher.TYPES.PLATFORM_MESSAGE,
         resourceWatcher.TYPES.NETWORK_EVENT,
         resourceWatcher.TYPES.NETWORK_EVENT_STACKTRACE,
+        resourceWatcher.TYPES.CLONED_CONTENT_PROCESS_MESSAGE,
       ],
       {
         onAvailable: this._onResourceAvailable,
@@ -433,15 +434,7 @@ class WebConsoleUI {
     // This is a top level target. It may update on process switches
     // when navigating to another domain.
     if (targetFront.isTopLevel) {
-      const needContentProcessMessagesListener =
+      this.proxy = new WebConsoleConnectionProxy(this, targetFront);
-        targetFront.isParentProcess &&
-        !targetFront.isAddon &&
-        !this.fissionSupport;
-      this.proxy = new WebConsoleConnectionProxy(
-        this,
-        targetFront,
-        needContentProcessMessagesListener
-      );
       await this.proxy.connect();
       dispatchTargetAvailable();
       return;

devtools/server/actors/webconsole.js

@@ -754,8 +754,8 @@ const WebConsoleActor = ActorClassWithSpec(webconsoleSpec, {
             break;
           }
           if (!this.contentProcessListener) {
-            this.contentProcessListener = new ContentProcessListener(
+            this.contentProcessListener = new ContentProcessListener(message =>
-              this.onConsoleAPICall
+              this.onConsoleAPICall(message, { clonedFromContentProcess: true })
             );
           }
           startedListeners.push(event);
@@ -1788,10 +1788,13 @@ const WebConsoleActor = ActorClassWithSpec(webconsoleSpec, {
    * @see ConsoleAPIListener
    * @param object message
    *        The console API call we need to send to the remote client.
+   * @param object extraProperties
+   *        an object whose properties will be folded in the packet that is emitted.
    */
-  onConsoleAPICall: function(message) {
+  onConsoleAPICall: function(message, extraProperties = {}) {
     this.emit("consoleAPICall", {
       message: this.prepareConsoleMessageForRemote(message),
+      ...extraProperties,
     });
   },
 

devtools/shared/resources/legacy-listeners/cloned-content-process-messages.js

@@ -0,0 +1,51 @@
+/* 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";
+
+const {
+  ResourceWatcher,
+} = require("devtools/shared/resources/resource-watcher");
+
+const Services = require("Services");
+
+// This legacy listener is used to retrieve content messages that are cloned from content
+// process to the parent process for BrowserConsole and BrowserToolbox when multiprocess
+// support is disabled.
+module.exports = async function({ targetList, targetFront, onAvailable }) {
+  const browserToolboxFissionSupport = Services.prefs.getBoolPref(
+    "devtools.browsertoolbox.fission",
+    false
+  );
+
+  // Content process messages should only be retrieved for top-level browser console and
+  // browser toolbox targets, when fission support is disabled.
+  const acceptTarget =
+    targetFront.isParentProcess &&
+    !targetFront.isAddon &&
+    !browserToolboxFissionSupport;
+
+  if (!acceptTarget) {
+    return;
+  }
+
+  const webConsoleFront = await targetFront.getFront("console");
+  if (webConsoleFront.isDestroyed()) {
+    return;
+  }
+
+  // Request notifying about new messages
+  await webConsoleFront.startListeners(["ContentProcessMessages"]);
+
+  // ContentProcessMessages are sent through the consoleAPICall event, and are seen as
+  // console api messages on the client.
+  webConsoleFront.on("consoleAPICall", packet => {
+    // Ignore console messages that aren't from the content process
+    if (!packet.clonedFromContentProcess) {
+      return;
+    }
+    packet.resourceType = ResourceWatcher.TYPES.CONSOLE_MESSAGE;
+    onAvailable([packet]);
+  });
+};

devtools/shared/resources/legacy-listeners/console-messages.js

@@ -48,6 +48,12 @@ module.exports = async function({ targetList, targetFront, onAvailable }) {
 
   // Forward new message events
   webConsoleFront.on("consoleAPICall", message => {
+    // Ignore console messages that are cloned from the content process (they're handled
+    // by the cloned-content-process-messages legacy listener).
+    if (message.clonedFromContentProcess) {
+      return;
+    }
+
     message.resourceType = ResourceWatcher.TYPES.CONSOLE_MESSAGE;
     onAvailable([message]);
   });

devtools/shared/resources/legacy-listeners/moz.build

@@ -4,6 +4,7 @@
 
 DevToolsModules(
     "cache-storage.js",
+    "cloned-content-process-messages.js",
     "console-messages.js",
     "cookie.js",
     "css-changes.js",

devtools/shared/resources/resource-watcher.js

@@ -866,6 +866,8 @@ ResourceWatcher.TYPES = ResourceWatcher.prototype.TYPES = {
   CSS_MESSAGE: "css-message",
   ERROR_MESSAGE: "error-message",
   PLATFORM_MESSAGE: "platform-message",
+  // Legacy listener only. Can be removed in Bug 1625937.
+  CLONED_CONTENT_PROCESS_MESSAGE: "cloned-content-process-message",
   DOCUMENT_EVENT: "document-event",
   ROOT_NODE: "root-node",
   STYLESHEET: "stylesheet",
@@ -898,6 +900,8 @@ const LegacyListeners = {
     .ERROR_MESSAGE]: require("devtools/shared/resources/legacy-listeners/error-messages"),
   [ResourceWatcher.TYPES
     .PLATFORM_MESSAGE]: require("devtools/shared/resources/legacy-listeners/platform-messages"),
+  [ResourceWatcher.TYPES
+    .CLONED_CONTENT_PROCESS_MESSAGE]: require("devtools/shared/resources/legacy-listeners/cloned-content-process-messages"),
   async [ResourceWatcher.TYPES.DOCUMENT_EVENT]({
     targetList,
     targetFront,

devtools/shared/specs/webconsole.js

@@ -78,6 +78,7 @@ const webconsoleSpecPrototype = {
     },
     consoleAPICall: {
       message: Option(0, "json"),
+      clonedFromContentProcess: Option(0, "nullable:boolean"),
     },
     reflowActivity: {
       interruptible: Option(0, "boolean"),