Adding upstream version 124.0.1.upstream/124.0.1

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1308 insertions, 0 deletions

diff --git a/toolkit/components/extensions/ExtensionContent.sys.mjs b/toolkit/components/extensions/ExtensionContent.sys.mjs
new file mode 100644
index 0000000000..131d555bf0
--- /dev/null
+++ b/toolkit/components/extensions/ExtensionContent.sys.mjs
@@ -0,0 +1,1308 @@
+/* -*- Mode: indent-tabs-mode: nil; js-indent-level: 2 -*- */
+/* vim: set sts=2 sw=2 et tw=80: */
+/* 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/. */
+
+import { XPCOMUtils } from "resource://gre/modules/XPCOMUtils.sys.mjs";
+import { AppConstants } from "resource://gre/modules/AppConstants.sys.mjs";
+
+const lazy = {};
+
+ChromeUtils.defineESModuleGetters(lazy, {
+  ExtensionProcessScript:
+    "resource://gre/modules/ExtensionProcessScript.sys.mjs",
+  ExtensionTelemetry: "resource://gre/modules/ExtensionTelemetry.sys.mjs",
+  LanguageDetector:
+    "resource://gre/modules/translation/LanguageDetector.sys.mjs",
+  Schemas: "resource://gre/modules/Schemas.sys.mjs",
+  WebNavigationFrames: "resource://gre/modules/WebNavigationFrames.sys.mjs",
+});
+
+XPCOMUtils.defineLazyServiceGetter(
+  lazy,
+  "styleSheetService",
+  "@mozilla.org/content/style-sheet-service;1",
+  "nsIStyleSheetService"
+);
+
+const Timer = Components.Constructor(
+  "@mozilla.org/timer;1",
+  "nsITimer",
+  "initWithCallback"
+);
+
+const ScriptError = Components.Constructor(
+  "@mozilla.org/scripterror;1",
+  "nsIScriptError",
+  "initWithWindowID"
+);
+
+import {
+  ExtensionChild,
+  ExtensionActivityLogChild,
+} from "resource://gre/modules/ExtensionChild.sys.mjs";
+import { ExtensionCommon } from "resource://gre/modules/ExtensionCommon.sys.mjs";
+import { ExtensionUtils } from "resource://gre/modules/ExtensionUtils.sys.mjs";
+
+const {
+  DefaultMap,
+  DefaultWeakMap,
+  getInnerWindowID,
+  promiseDocumentIdle,
+  promiseDocumentLoaded,
+  promiseDocumentReady,
+} = ExtensionUtils;
+
+const {
+  BaseContext,
+  CanOfAPIs,
+  SchemaAPIManager,
+  defineLazyGetter,
+  redefineGetter,
+  runSafeSyncWithoutClone,
+} = ExtensionCommon;
+
+const { BrowserExtensionContent, ChildAPIManager, Messenger } = ExtensionChild;
+
+ChromeUtils.defineLazyGetter(lazy, "isContentScriptProcess", () => {
+  return (
+    Services.appinfo.processType === Services.appinfo.PROCESS_TYPE_CONTENT ||
+    !WebExtensionPolicy.useRemoteWebExtensions ||
+    // Thunderbird still loads some content in the parent process.
+    AppConstants.MOZ_APP_NAME == "thunderbird"
+  );
+});
+
+var DocumentManager;
+
+const CATEGORY_EXTENSION_SCRIPTS_CONTENT = "webextension-scripts-content";
+
+var apiManager = new (class extends SchemaAPIManager {
+  constructor() {
+    super("content", lazy.Schemas);
+    this.initialized = false;
+  }
+
+  lazyInit() {
+    if (!this.initialized) {
+      this.initialized = true;
+      this.initGlobal();
+      for (let { value } of Services.catMan.enumerateCategory(
+        CATEGORY_EXTENSION_SCRIPTS_CONTENT
+      )) {
+        this.loadScript(value);
+      }
+    }
+  }
+})();
+
+const SCRIPT_EXPIRY_TIMEOUT_MS = 5 * 60 * 1000;
+const SCRIPT_CLEAR_TIMEOUT_MS = 5 * 1000;
+
+const CSS_EXPIRY_TIMEOUT_MS = 30 * 60 * 1000;
+const CSSCODE_EXPIRY_TIMEOUT_MS = 10 * 60 * 1000;
+
+const scriptCaches = new WeakSet();
+const sheetCacheDocuments = new DefaultWeakMap(() => new WeakSet());
+
+class CacheMap extends DefaultMap {
+  constructor(timeout, getter, extension) {
+    super(getter);
+
+    this.expiryTimeout = timeout;
+
+    scriptCaches.add(this);
+
+    // This ensures that all the cached scripts and stylesheets are deleted
+    // from the cache and the xpi is no longer actively used.
+    // See Bug 1435100 for rationale.
+    extension.once("shutdown", () => {
+      this.clear(-1);
+    });
+  }
+
+  get(url) {
+    let promise = super.get(url);
+
+    promise.lastUsed = Date.now();
+    if (promise.timer) {
+      promise.timer.cancel();
+    }
+    promise.timer = Timer(
+      this.delete.bind(this, url),
+      this.expiryTimeout,
+      Ci.nsITimer.TYPE_ONE_SHOT
+    );
+
+    return promise;
+  }
+
+  delete(url) {
+    if (this.has(url)) {
+      super.get(url).timer.cancel();
+    }
+
+    return super.delete(url);
+  }
+
+  clear(timeout = SCRIPT_CLEAR_TIMEOUT_MS) {
+    let now = Date.now();
+    for (let [url, promise] of this.entries()) {
+      // Delete the entry if expired or if clear has been called with timeout -1
+      // (which is used to force the cache to clear all the entries, e.g. when the
+      // extension is shutting down).
+      if (timeout === -1 || now - promise.lastUsed >= timeout) {
+        this.delete(url);
+      }
+    }
+  }
+}
+
+class ScriptCache extends CacheMap {
+  constructor(options, extension) {
+    super(
+      SCRIPT_EXPIRY_TIMEOUT_MS,
+      url => {
+        let promise = ChromeUtils.compileScript(url, options);
+        promise.then(script => {
+          promise.script = script;
+        });
+        return promise;
+      },
+      extension
+    );
+  }
+}
+
+/**
+ * Shared base class for the two specialized CSS caches:
+ * CSSCache (for the "url"-based stylesheets) and CSSCodeCache
+ * (for the stylesheet defined by plain CSS content as a string).
+ */
+class BaseCSSCache extends CacheMap {
+  constructor(expiryTimeout, defaultConstructor, extension) {
+    super(expiryTimeout, defaultConstructor, extension);
+  }
+
+  addDocument(key, document) {
+    sheetCacheDocuments.get(this.get(key)).add(document);
+  }
+
+  deleteDocument(key, document) {
+    sheetCacheDocuments.get(this.get(key)).delete(document);
+  }
+
+  delete(key) {
+    if (this.has(key)) {
+      let promise = this.get(key);
+
+      // Never remove a sheet from the cache if it's still being used by a
+      // document. Rule processors can be shared between documents with the
+      // same preloaded sheet, so we only lose by removing them while they're
+      // still in use.
+      let docs = ChromeUtils.nondeterministicGetWeakSetKeys(
+        sheetCacheDocuments.get(promise)
+      );
+      if (docs.length) {
+        return;
+      }
+    }
+
+    return super.delete(key);
+  }
+}
+
+/**
+ * Cache of the preloaded stylesheet defined by url.
+ */
+class CSSCache extends BaseCSSCache {
+  constructor(sheetType, extension) {
+    super(
+      CSS_EXPIRY_TIMEOUT_MS,
+      url => {
+        let uri = Services.io.newURI(url);
+        return lazy.styleSheetService
+          .preloadSheetAsync(uri, sheetType)
+          .then(sheet => {
+            return { url, sheet };
+          });
+      },
+      extension
+    );
+  }
+}
+
+/**
+ * Cache of the preloaded stylesheet defined by plain CSS content as a string,
+ * the key of the cached stylesheet is the hash of its "CSSCode" string.
+ */
+class CSSCodeCache extends BaseCSSCache {
+  constructor(sheetType, extension) {
+    super(
+      CSSCODE_EXPIRY_TIMEOUT_MS,
+      hash => {
+        if (!this.has(hash)) {
+          // Do not allow the getter to be used to lazily create the cached stylesheet,
+          // the cached CSSCode stylesheet has to be explicitly set.
+          throw new Error(
+            "Unexistent cached cssCode stylesheet: " + Error().stack
+          );
+        }
+
+        return super.get(hash);
+      },
+      extension
+    );
+
+    // Store the preferred sheetType (used to preload the expected stylesheet type in
+    // the addCSSCode method).
+    this.sheetType = sheetType;
+  }
+
+  addCSSCode(hash, cssCode) {
+    if (this.has(hash)) {
+      // This cssCode have been already cached, no need to create it again.
+      return;
+    }
+    // The `webext=style` portion is added metadata to help us distinguish
+    // different kinds of data URL loads that are triggered with the
+    // SystemPrincipal. It shall be removed with bug 1699425.
+    const uri = Services.io.newURI(
+      "data:text/css;extension=style;charset=utf-8," +
+        encodeURIComponent(cssCode)
+    );
+    const value = lazy.styleSheetService
+      .preloadSheetAsync(uri, this.sheetType)
+      .then(sheet => {
+        return { sheet, uri };
+      });
+
+    super.set(hash, value);
+  }
+}
+
+defineLazyGetter(
+  BrowserExtensionContent.prototype,
+  "staticScripts",
+  function () {
+    return new ScriptCache({ hasReturnValue: false }, this);
+  }
+);
+
+defineLazyGetter(
+  BrowserExtensionContent.prototype,
+  "dynamicScripts",
+  function () {
+    return new ScriptCache({ hasReturnValue: true }, this);
+  }
+);
+
+defineLazyGetter(BrowserExtensionContent.prototype, "userCSS", function () {
+  return new CSSCache(Ci.nsIStyleSheetService.USER_SHEET, this);
+});
+
+defineLazyGetter(BrowserExtensionContent.prototype, "authorCSS", function () {
+  return new CSSCache(Ci.nsIStyleSheetService.AUTHOR_SHEET, this);
+});
+
+// These two caches are similar to the above but specialized to cache the cssCode
+// using an hash computed from the cssCode string as the key (instead of the generated data
+// URI which can be pretty long for bigger injected cssCode).
+defineLazyGetter(BrowserExtensionContent.prototype, "userCSSCode", function () {
+  return new CSSCodeCache(Ci.nsIStyleSheetService.USER_SHEET, this);
+});
+
+defineLazyGetter(
+  BrowserExtensionContent.prototype,
+  "authorCSSCode",
+  function () {
+    return new CSSCodeCache(Ci.nsIStyleSheetService.AUTHOR_SHEET, this);
+  }
+);
+
+// Represents a content script.
+class Script {
+  /**
+   * @param {BrowserExtensionContent} extension
+   * @param {WebExtensionContentScript|object} matcher
+   *        An object with a "matchesWindowGlobal" method and content script
+   *        execution details. This is usually a plain WebExtensionContentScript
+   *        except when the script is run via `tabs.executeScript`. In this
+   *        case, the object may have some extra properties:
+   *        wantReturnValue, removeCSS, cssOrigin, jsCode
+   */
+  constructor(extension, matcher) {
+    this.scriptType = "content_script";
+    this.extension = extension;
+    this.matcher = matcher;
+
+    this.runAt = this.matcher.runAt;
+    this.js = this.matcher.jsPaths;
+    this.css = this.matcher.cssPaths.slice();
+    this.cssCodeHash = null;
+
+    this.removeCSS = this.matcher.removeCSS;
+    this.cssOrigin = this.matcher.cssOrigin;
+
+    this.cssCache =
+      extension[this.cssOrigin === "user" ? "userCSS" : "authorCSS"];
+    this.cssCodeCache =
+      extension[this.cssOrigin === "user" ? "userCSSCode" : "authorCSSCode"];
+    this.scriptCache =
+      extension[matcher.wantReturnValue ? "dynamicScripts" : "staticScripts"];
+
+    /** @type {WeakSet<Document>} A set of documents injected into. */
+    this.injectedInto = new WeakSet();
+
+    if (matcher.wantReturnValue) {
+      this.compileScripts();
+      this.loadCSS();
+    }
+  }
+
+  get requiresCleanup() {
+    return !this.removeCSS && (!!this.css.length || this.cssCodeHash);
+  }
+
+  async addCSSCode(cssCode) {
+    if (!cssCode) {
+      return;
+    }
+
+    // Store the hash of the cssCode.
+    const buffer = await crypto.subtle.digest(
+      "SHA-1",
+      new TextEncoder().encode(cssCode)
+    );
+    this.cssCodeHash = String.fromCharCode(...new Uint16Array(buffer));
+
+    // Cache and preload the cssCode stylesheet.
+    this.cssCodeCache.addCSSCode(this.cssCodeHash, cssCode);
+  }
+
+  compileScripts() {
+    return this.js.map(url => this.scriptCache.get(url));
+  }
+
+  loadCSS() {
+    return this.css.map(url => this.cssCache.get(url));
+  }
+
+  preload() {
+    this.loadCSS();
+    this.compileScripts();
+  }
+
+  cleanup(window) {
+    if (this.requiresCleanup) {
+      if (window) {
+        let { windowUtils } = window;
+
+        let type =
+          this.cssOrigin === "user"
+            ? windowUtils.USER_SHEET
+            : windowUtils.AUTHOR_SHEET;
+
+        for (let url of this.css) {
+          this.cssCache.deleteDocument(url, window.document);
+
+          if (!window.closed) {
+            runSafeSyncWithoutClone(
+              windowUtils.removeSheetUsingURIString,
+              url,
+              type
+            );
+          }
+        }
+
+        const { cssCodeHash } = this;
+
+        if (cssCodeHash && this.cssCodeCache.has(cssCodeHash)) {
+          if (!window.closed) {
+            this.cssCodeCache.get(cssCodeHash).then(({ uri }) => {
+              runSafeSyncWithoutClone(windowUtils.removeSheet, uri, type);
+            });
+          }
+          this.cssCodeCache.deleteDocument(cssCodeHash, window.document);
+        }
+      }
+
+      // Clear any sheets that were kept alive past their timeout as
+      // a result of living in this document.
+      this.cssCodeCache.clear(CSSCODE_EXPIRY_TIMEOUT_MS);
+      this.cssCache.clear(CSS_EXPIRY_TIMEOUT_MS);
+    }
+  }
+
+  matchesWindowGlobal(windowGlobal, ignorePermissions) {
+    return this.matcher.matchesWindowGlobal(windowGlobal, ignorePermissions);
+  }
+
+  async injectInto(window, reportExceptions = true) {
+    if (
+      !lazy.isContentScriptProcess ||
+      this.injectedInto.has(window.document)
+    ) {
+      return;
+    }
+    this.injectedInto.add(window.document);
+
+    let context = this.extension.getContext(window);
+    for (let script of this.matcher.jsPaths) {
+      context.logActivity(this.scriptType, script, {
+        url: window.location.href,
+      });
+    }
+
+    try {
+      if (this.runAt === "document_end") {
+        await promiseDocumentReady(window.document);
+      } else if (this.runAt === "document_idle") {
+        await Promise.race([
+          promiseDocumentIdle(window),
+          promiseDocumentLoaded(window.document),
+        ]);
+      }
+
+      return this.inject(context, reportExceptions);
+    } catch (e) {
+      return Promise.reject(context.normalizeError(e));
+    }
+  }
+
+  /**
+   * Tries to inject this script into the given window and sandbox, if
+   * there are pending operations for the window's current load state.
+   *
+   * @param {ContentScriptContextChild} context
+   *        The content script context into which to inject the scripts.
+   * @param {boolean} reportExceptions
+   *        Defaults to true and reports any exception directly to the console
+   *        and no exception will be thrown out of this function.
+   * @returns {Promise<any>}
+   *        Resolves to the last value in the evaluated script, when
+   *        execution is complete.
+   */
+  async inject(context, reportExceptions = true) {
+    DocumentManager.lazyInit();
+    if (this.requiresCleanup) {
+      context.addScript(this);
+    }
+
+    const { cssCodeHash } = this;
+
+    let cssPromise;
+    if (this.css.length || cssCodeHash) {
+      let window = context.contentWindow;
+      let { windowUtils } = window;
+
+      let type =
+        this.cssOrigin === "user"
+          ? windowUtils.USER_SHEET
+          : windowUtils.AUTHOR_SHEET;
+
+      if (this.removeCSS) {
+        for (let url of this.css) {
+          this.cssCache.deleteDocument(url, window.document);
+
+          runSafeSyncWithoutClone(
+            windowUtils.removeSheetUsingURIString,
+            url,
+            type
+          );
+        }
+
+        if (cssCodeHash && this.cssCodeCache.has(cssCodeHash)) {
+          const { uri } = await this.cssCodeCache.get(cssCodeHash);
+          this.cssCodeCache.deleteDocument(cssCodeHash, window.document);
+
+          runSafeSyncWithoutClone(windowUtils.removeSheet, uri, type);
+        }
+      } else {
+        cssPromise = Promise.all(this.loadCSS()).then(sheets => {
+          let window = context.contentWindow;
+          if (!window) {
+            return;
+          }
+
+          for (let { url, sheet } of sheets) {
+            this.cssCache.addDocument(url, window.document);
+
+            runSafeSyncWithoutClone(windowUtils.addSheet, sheet, type);
+          }
+        });
+
+        if (cssCodeHash) {
+          cssPromise = cssPromise.then(async () => {
+            const { sheet } = await this.cssCodeCache.get(cssCodeHash);
+            this.cssCodeCache.addDocument(cssCodeHash, window.document);
+
+            runSafeSyncWithoutClone(windowUtils.addSheet, sheet, type);
+          });
+        }
+
+        // We're loading stylesheets via the stylesheet service, which means
+        // that the normal mechanism for blocking layout and onload for pending
+        // stylesheets aren't in effect (since there's no document to block). So
+        // we need to do something custom here, similar to what we do for
+        // scripts. Blocking parsing is overkill, since we really just want to
+        // block layout and onload. But we have an API to do the former and not
+        // the latter, so we do it that way. This hopefully isn't a performance
+        // problem since there are no network loads involved, and since we cache
+        // the stylesheets on first load. We should fix this up if it does becomes
+        // a problem.
+        if (this.css.length) {
+          context.contentWindow.document.blockParsing(cssPromise, {
+            blockScriptCreated: false,
+          });
+        }
+      }
+    }
+
+    let scripts = this.getCompiledScripts(context);
+    if (scripts instanceof Promise) {
+      scripts = await scripts;
+    }
+
+    // Make sure we've injected any related CSS before we run content scripts.
+    await cssPromise;
+
+    let result;
+
+    const { extension } = context;
+
+    // The evaluations below may throw, in which case the promise will be
+    // automatically rejected.
+    lazy.ExtensionTelemetry.contentScriptInjection.stopwatchStart(
+      extension,
+      context
+    );
+    try {
+      for (let script of scripts) {
+        result = script.executeInGlobal(context.cloneScope, {
+          reportExceptions,
+        });
+      }
+
+      if (this.matcher.jsCode) {
+        result = Cu.evalInSandbox(
+          this.matcher.jsCode,
+          context.cloneScope,
+          "latest",
+          "sandbox eval code",
+          1
+        );
+      }
+    } finally {
+      lazy.ExtensionTelemetry.contentScriptInjection.stopwatchFinish(
+        extension,
+        context
+      );
+    }
+
+    return result;
+  }
+
+  /**
+   *  Get the compiled scripts (if they are already precompiled and cached) or a promise which resolves
+   *  to the precompiled scripts (once they have been compiled and cached).
+   *
+   * @param {ContentScriptContextChild} context
+   *        The document to block the parsing on, if the scripts are not yet precompiled and cached.
+   *
+   * @returns {Array<PreloadedScript> | Promise<Array<PreloadedScript>>}
+   *          Returns an array of preloaded scripts if they are already available, or a promise which
+   *          resolves to the array of the preloaded scripts once they are precompiled and cached.
+   */
+  getCompiledScripts(context) {
+    let scriptPromises = this.compileScripts();
+    let scripts = scriptPromises.map(promise => promise.script);
+
+    // If not all scripts are already available in the cache, block
+    // parsing and wait all promises to resolve.
+    if (!scripts.every(script => script)) {
+      let promise = Promise.all(scriptPromises);
+
+      // If there is any syntax error, the script promises will be rejected.
+      //
+      // Notify the exception directly to the console so that it can
+      // be displayed in the web console by flagging the error with the right
+      // innerWindowID.
+      for (const p of scriptPromises) {
+        p.catch(error => {
+          Services.console.logMessage(
+            new ScriptError(
+              `${error.name}: ${error.message}`,
+              error.fileName,
+              null,
+              error.lineNumber,
+              error.columnNumber,
+              Ci.nsIScriptError.errorFlag,
+              "content javascript",
+              context.innerWindowID
+            )
+          );
+        });
+      }
+
+      // If we're supposed to inject at the start of the document load,
+      // and we haven't already missed that point, block further parsing
+      // until the scripts have been loaded.
+      const { document } = context.contentWindow;
+      if (
+        this.runAt === "document_start" &&
+        document.readyState !== "complete"
+      ) {
+        document.blockParsing(promise, { blockScriptCreated: false });
+      }
+
+      return promise;
+    }
+
+    return scripts;
+  }
+}
+
+// Represents a user script.
+class UserScript extends Script {
+  /**
+   * @param {BrowserExtensionContent} extension
+   * @param {WebExtensionContentScript|object} matcher
+   *        An object with a "matchesWindowGlobal" method and content script
+   *        execution details.
+   */
+  constructor(extension, matcher) {
+    super(extension, matcher);
+    this.scriptType = "user_script";
+
+    // This is an opaque object that the extension provides, it is associated to
+    // the particular userScript and it is passed as a parameter to the custom
+    // userScripts APIs defined by the extension.
+    this.scriptMetadata = matcher.userScriptOptions.scriptMetadata;
+    this.apiScriptURL =
+      extension.manifest.user_scripts &&
+      extension.manifest.user_scripts.api_script;
+
+    // Add the apiScript to the js scripts to compile.
+    if (this.apiScriptURL) {
+      this.js = [this.apiScriptURL].concat(this.js);
+    }
+
+    // WeakMap<ContentScriptContextChild, Sandbox>
+    this.sandboxes = new DefaultWeakMap(context => {
+      return this.createSandbox(context);
+    });
+  }
+
+  async inject(context) {
+    DocumentManager.lazyInit();
+
+    let scripts = this.getCompiledScripts(context);
+    if (scripts instanceof Promise) {
+      scripts = await scripts;
+    }
+
+    let apiScript, sandboxScripts;
+
+    if (this.apiScriptURL) {
+      [apiScript, ...sandboxScripts] = scripts;
+    } else {
+      sandboxScripts = scripts;
+    }
+
+    // Load and execute the API script once per context.
+    if (apiScript) {
+      context.executeAPIScript(apiScript);
+    }
+
+    let userScriptSandbox = this.sandboxes.get(context);
+
+    context.callOnClose({
+      close: () => {
+        // Destroy the userScript sandbox when the related ContentScriptContextChild instance
+        // is being closed.
+        this.sandboxes.delete(context);
+        Cu.nukeSandbox(userScriptSandbox);
+      },
+    });
+
+    // Notify listeners subscribed to the userScripts.onBeforeScript API event,
+    // to allow extension API script to provide its custom APIs to the userScript.
+    if (apiScript) {
+      context.userScriptsEvents.emit(
+        "on-before-script",
+        this.scriptMetadata,
+        userScriptSandbox
+      );
+    }
+
+    for (let script of sandboxScripts) {
+      script.executeInGlobal(userScriptSandbox);
+    }
+  }
+
+  createSandbox(context) {
+    const { contentWindow } = context;
+    const contentPrincipal = contentWindow.document.nodePrincipal;
+    const ssm = Services.scriptSecurityManager;
+
+    let principal;
+    if (contentPrincipal.isSystemPrincipal) {
+      principal = ssm.createNullPrincipal(contentPrincipal.originAttributes);
+    } else {
+      principal = [contentPrincipal];
+    }
+
+    const sandbox = Cu.Sandbox(principal, {
+      sandboxName: `User Script registered by ${this.extension.policy.debugName}`,
+      sandboxPrototype: contentWindow,
+      sameZoneAs: contentWindow,
+      wantXrays: true,
+      wantGlobalProperties: ["XMLHttpRequest", "fetch", "WebSocket"],
+      originAttributes: contentPrincipal.originAttributes,
+      metadata: {
+        "inner-window-id": context.innerWindowID,
+        addonId: this.extension.policy.id,
+      },
+    });
+
+    return sandbox;
+  }
+}
+
+var contentScripts = new DefaultWeakMap(matcher => {
+  const extension = lazy.ExtensionProcessScript.extensions.get(
+    matcher.extension
+  );
+
+  if ("userScriptOptions" in matcher) {
+    return new UserScript(extension, matcher);
+  }
+
+  return new Script(extension, matcher);
+});
+
+/**
+ * An execution context for semi-privileged extension content scripts.
+ *
+ * This is the child side of the ContentScriptContextParent class
+ * defined in ExtensionParent.jsm.
+ */
+class ContentScriptContextChild extends BaseContext {
+  constructor(extension, contentWindow) {
+    super("content_child", extension);
+
+    this.setContentWindow(contentWindow);
+
+    let frameId = lazy.WebNavigationFrames.getFrameId(contentWindow);
+    this.frameId = frameId;
+
+    this.browsingContextId = contentWindow.docShell.browsingContext.id;
+
+    this.scripts = [];
+
+    let contentPrincipal = contentWindow.document.nodePrincipal;
+    let ssm = Services.scriptSecurityManager;
+
+    // Copy origin attributes from the content window origin attributes to
+    // preserve the user context id.
+    let attrs = contentPrincipal.originAttributes;
+    let extensionPrincipal = ssm.createContentPrincipal(
+      this.extension.baseURI,
+      attrs
+    );
+
+    this.isExtensionPage = contentPrincipal.equals(extensionPrincipal);
+
+    if (this.isExtensionPage) {
+      // This is an iframe with content script API enabled and its principal
+      // should be the contentWindow itself. We create a sandbox with the
+      // contentWindow as principal and with X-rays disabled because it
+      // enables us to create the APIs object in this sandbox object and then
+      // copying it into the iframe's window.  See bug 1214658.
+      this.sandbox = Cu.Sandbox(contentWindow, {
+        sandboxName: `Web-Accessible Extension Page ${extension.policy.debugName}`,
+        sandboxPrototype: contentWindow,
+        sameZoneAs: contentWindow,
+        wantXrays: false,
+        isWebExtensionContentScript: true,
+      });
+    } else {
+      let principal;
+      if (contentPrincipal.isSystemPrincipal) {
+        // Make sure we don't hand out the system principal by accident.
+        // Also make sure that the null principal has the right origin attributes.
+        principal = ssm.createNullPrincipal(attrs);
+      } else {
+        principal = [contentPrincipal, extensionPrincipal];
+      }
+      // This metadata is required by the Developer Tools, in order for
+      // the content script to be associated with both the extension and
+      // the tab holding the content page.
+      let metadata = {
+        "inner-window-id": this.innerWindowID,
+        addonId: extensionPrincipal.addonId,
+      };
+
+      let isMV2 = extension.manifestVersion == 2;
+      let wantGlobalProperties;
+      if (isMV2) {
+        // In MV2, fetch/XHR support cross-origin requests.
+        // WebSocket was also included to avoid CSP effects (bug 1676024).
+        wantGlobalProperties = ["XMLHttpRequest", "fetch", "WebSocket"];
+      } else {
+        // In MV3, fetch/XHR have the same capabilities as the web page.
+        wantGlobalProperties = [];
+      }
+      this.sandbox = Cu.Sandbox(principal, {
+        metadata,
+        sandboxName: `Content Script ${extension.policy.debugName}`,
+        sandboxPrototype: contentWindow,
+        sameZoneAs: contentWindow,
+        wantXrays: true,
+        isWebExtensionContentScript: true,
+        wantExportHelpers: true,
+        wantGlobalProperties,
+        originAttributes: attrs,
+      });
+
+      // Preserve a copy of the original Error and Promise globals from the sandbox object,
+      // which are used in the WebExtensions internals (before any content script code had
+      // any chance to redefine them).
+      this.cloneScopePromise = this.sandbox.Promise;
+      this.cloneScopeError = this.sandbox.Error;
+
+      if (isMV2) {
+        // Preserve a copy of the original window's XMLHttpRequest and fetch
+        // in a content object (fetch is manually binded to the window
+        // to prevent it from raising a TypeError because content object is not
+        // a real window).
+        Cu.evalInSandbox(
+          `
+          this.content = {
+            XMLHttpRequest: window.XMLHttpRequest,
+            fetch: window.fetch.bind(window),
+            WebSocket: window.WebSocket,
+          };
+
+          window.JSON = JSON;
+          window.XMLHttpRequest = XMLHttpRequest;
+          window.fetch = fetch;
+          window.WebSocket = WebSocket;
+        `,
+          this.sandbox
+        );
+      } else {
+        // The sandbox's JSON API can deal with values from the sandbox and the
+        // contentWindow, but window.JSON cannot (and it could potentially be
+        // spoofed by the web page). jQuery.parseJSON relies on window.JSON.
+        Cu.evalInSandbox("window.JSON = JSON;", this.sandbox);
+      }
+    }
+
+    Object.defineProperty(this, "principal", {
+      value: Cu.getObjectPrincipal(this.sandbox),
+      enumerable: true,
+      configurable: true,
+    });
+
+    this.url = contentWindow.location.href;
+
+    lazy.Schemas.exportLazyGetter(
+      this.sandbox,
+      "browser",
+      () => this.chromeObj
+    );
+    lazy.Schemas.exportLazyGetter(this.sandbox, "chrome", () => this.chromeObj);
+
+    // Keep track if the userScript API script has been already executed in this context
+    // (e.g. because there are more then one UserScripts that match the related webpage
+    // and so the UserScript apiScript has already been executed).
+    this.hasUserScriptAPIs = false;
+
+    // A lazy created EventEmitter related to userScripts-specific events.
+    defineLazyGetter(this, "userScriptsEvents", () => {
+      return new ExtensionCommon.EventEmitter();
+    });
+  }
+
+  injectAPI() {
+    if (!this.isExtensionPage) {
+      throw new Error("Cannot inject extension API into non-extension window");
+    }
+
+    // This is an iframe with content script API enabled (See Bug 1214658)
+    lazy.Schemas.exportLazyGetter(
+      this.contentWindow,
+      "browser",
+      () => this.chromeObj
+    );
+    lazy.Schemas.exportLazyGetter(
+      this.contentWindow,
+      "chrome",
+      () => this.chromeObj
+    );
+  }
+
+  async logActivity(type, name, data) {
+    ExtensionActivityLogChild.log(this, type, name, data);
+  }
+
+  get cloneScope() {
+    return this.sandbox;
+  }
+
+  async executeAPIScript(apiScript) {
+    // Execute the UserScript apiScript only once per context (e.g. more then one UserScripts
+    // match the same webpage and the apiScript has already been executed).
+    if (apiScript && !this.hasUserScriptAPIs) {
+      this.hasUserScriptAPIs = true;
+      apiScript.executeInGlobal(this.cloneScope);
+    }
+  }
+
+  addScript(script) {
+    if (script.requiresCleanup) {
+      this.scripts.push(script);
+    }
+  }
+
+  close() {
+    super.unload();
+
+    // Cleanup the scripts even if the contentWindow have been destroyed.
+    for (let script of this.scripts) {
+      script.cleanup(this.contentWindow);
+    }
+
+    if (this.contentWindow) {
+      // Overwrite the content script APIs with an empty object if the APIs objects are still
+      // defined in the content window (See Bug 1214658).
+      if (this.isExtensionPage) {
+        Cu.createObjectIn(this.contentWindow, { defineAs: "browser" });
+        Cu.createObjectIn(this.contentWindow, { defineAs: "chrome" });
+      }
+    }
+    Cu.nukeSandbox(this.sandbox);
+
+    this.sandbox = null;
+  }
+
+  get childManager() {
+    apiManager.lazyInit();
+    let can = new CanOfAPIs(this, apiManager, {});
+    let childManager = new ChildAPIManager(this, this.messageManager, can, {
+      envType: "content_parent",
+      url: this.url,
+    });
+    this.callOnClose(childManager);
+    return redefineGetter(this, "childManager", childManager);
+  }
+
+  get chromeObj() {
+    let chromeObj = Cu.createObjectIn(this.sandbox);
+    this.childManager.inject(chromeObj);
+    return redefineGetter(this, "chromeObj", chromeObj);
+  }
+
+  get messenger() {
+    return redefineGetter(this, "messenger", new Messenger(this));
+  }
+}
+
+// Responsible for creating ExtensionContexts and injecting content
+// scripts into them when new documents are created.
+DocumentManager = {
+  // Map[windowId -> Map[ExtensionChild -> ContentScriptContextChild]]
+  contexts: new Map(),
+
+  initialized: false,
+
+  lazyInit() {
+    if (this.initialized) {
+      return;
+    }
+    this.initialized = true;
+
+    Services.obs.addObserver(this, "inner-window-destroyed");
+    Services.obs.addObserver(this, "memory-pressure");
+  },
+
+  uninit() {
+    Services.obs.removeObserver(this, "inner-window-destroyed");
+    Services.obs.removeObserver(this, "memory-pressure");
+  },
+
+  observers: {
+    "inner-window-destroyed"(subject, topic, data) {
+      let windowId = subject.QueryInterface(Ci.nsISupportsPRUint64).data;
+
+      // Close any existent content-script context for the destroyed window.
+      if (this.contexts.has(windowId)) {
+        let extensions = this.contexts.get(windowId);
+        for (let context of extensions.values()) {
+          context.close();
+        }
+
+        this.contexts.delete(windowId);
+      }
+    },
+    "memory-pressure"(subject, topic, data) {
+      let timeout = data === "heap-minimize" ? 0 : undefined;
+
+      for (let cache of ChromeUtils.nondeterministicGetWeakSetKeys(
+        scriptCaches
+      )) {
+        cache.clear(timeout);
+      }
+    },
+  },
+
+  /**
+   * @param {object} subject
+   * @param {keyof typeof DocumentManager.observers} topic
+   * @param {any} data
+   */
+  observe(subject, topic, data) {
+    this.observers[topic].call(this, subject, topic, data);
+  },
+
+  shutdownExtension(extension) {
+    for (let extensions of this.contexts.values()) {
+      let context = extensions.get(extension);
+      if (context) {
+        context.close();
+        extensions.delete(extension);
+      }
+    }
+  },
+
+  getContexts(window) {
+    let winId = getInnerWindowID(window);
+
+    let extensions = this.contexts.get(winId);
+    if (!extensions) {
+      extensions = new Map();
+      this.contexts.set(winId, extensions);
+    }
+
+    return extensions;
+  },
+
+  // For test use only.
+  getContext(extensionId, window) {
+    for (let [extension, context] of this.getContexts(window)) {
+      if (extension.id === extensionId) {
+        return context;
+      }
+    }
+  },
+
+  getContentScriptGlobals(window) {
+    let extensions = this.contexts.get(getInnerWindowID(window));
+
+    if (extensions) {
+      return Array.from(extensions.values(), ctx => ctx.sandbox);
+    }
+
+    return [];
+  },
+
+  initExtensionContext(extension, window) {
+    extension.getContext(window).injectAPI();
+  },
+};
+
+export var ExtensionContent = {
+  BrowserExtensionContent,
+
+  contentScripts,
+
+  shutdownExtension(extension) {
+    DocumentManager.shutdownExtension(extension);
+  },
+
+  // This helper is exported to be integrated in the devtools RDP actors,
+  // that can use it to retrieve the existent WebExtensions ContentScripts
+  // of a target window and be able to show the ContentScripts source in the
+  // DevTools Debugger panel.
+  getContentScriptGlobals(window) {
+    return DocumentManager.getContentScriptGlobals(window);
+  },
+
+  initExtensionContext(extension, window) {
+    DocumentManager.initExtensionContext(extension, window);
+  },
+
+  getContext(extension, window) {
+    let extensions = DocumentManager.getContexts(window);
+
+    let context = extensions.get(extension);
+    if (!context) {
+      context = new ContentScriptContextChild(extension, window);
+      extensions.set(extension, context);
+    }
+    return context;
+  },
+
+  // For test use only.
+  getContextByExtensionId(extensionId, window) {
+    return DocumentManager.getContext(extensionId, window);
+  },
+
+  async handleDetectLanguage({ windows }) {
+    let wgc = WindowGlobalChild.getByInnerWindowId(windows[0]);
+    let doc = wgc.browsingContext.window.document;
+    await promiseDocumentReady(doc);
+
+    // The CLD2 library can analyze HTML, but that uses more memory, and
+    // emscripten can't shrink its heap, so we use plain text instead.
+    let encoder = Cu.createDocumentEncoder("text/plain");
+    encoder.init(doc, "text/plain", Ci.nsIDocumentEncoder.SkipInvisibleContent);
+
+    let result = await lazy.LanguageDetector.detectLanguage({
+      language:
+        doc.documentElement.getAttribute("xml:lang") ||
+        doc.documentElement.getAttribute("lang") ||
+        doc.contentLanguage ||
+        null,
+      tld: doc.location.hostname.match(/[a-z]*$/)[0],
+      text: encoder.encodeToStringWithMaxLength(60 * 1024),
+      encoding: doc.characterSet,
+    });
+    return result.language === "un" ? "und" : result.language;
+  },
+
+  // Activate MV3 content scripts in all same-origin frames for this tab.
+  handleActivateScripts({ options, windows }) {
+    let policy = WebExtensionPolicy.getByID(options.id);
+
+    // Order content scripts by run_at timing.
+    let runAt = { document_start: [], document_end: [], document_idle: [] };
+    for (let matcher of policy.contentScripts) {
+      runAt[matcher.runAt].push(this.contentScripts.get(matcher));
+    }
+
+    // If we got here, checks in TabManagerBase.activateScripts assert:
+    // 1) this is a MV3 extension, with Origin Controls,
+    // 2) with a host permission (or content script) for the tab's top origin,
+    // 3) and that host permission hasn't been granted yet.
+
+    // We treat the action click as implicit user's choice to activate the
+    // extension on the current site, so we can safely run (matching) content
+    // scripts in all sameOriginWithTop frames while ignoring host permission.
+
+    let { browsingContext } = WindowGlobalChild.getByInnerWindowId(windows[0]);
+    for (let bc of browsingContext.getAllBrowsingContextsInSubtree()) {
+      let wgc = bc.currentWindowContext.windowGlobalChild;
+      if (wgc?.sameOriginWithTop) {
+        // This is TOCTOU safe: if a frame navigated after same-origin check,
+        // wgc.isClosed would be true and .matchesWindowGlobal() would fail.
+        const runScript = cs => {
+          if (cs.matchesWindowGlobal(wgc, /* ignorePermissions */ true)) {
+            return cs.injectInto(bc.window);
+          }
+        };
+
+        // Inject all matching content scripts in proper run_at order.
+        Promise.all(runAt.document_start.map(runScript))
+          .then(() => Promise.all(runAt.document_end.map(runScript)))
+          .then(() => Promise.all(runAt.document_idle.map(runScript)));
+      }
+    }
+  },
+
+  // Used to executeScript, insertCSS and removeCSS.
+  async handleActorExecute({ options, windows }) {
+    let policy = WebExtensionPolicy.getByID(options.extensionId);
+    // `WebExtensionContentScript` uses `MozDocumentMatcher::Matches` to ensure
+    // that a script can be run in a document. That requires either `frameId`
+    // or `allFrames` to be set. When `frameIds` (plural) is used, we force
+    // `allFrames` to be `true` in order to match any frame. This is OK because
+    // `executeInWin()` below looks up the window for the given `frameIds`
+    // immediately before `script.injectInto()`. Due to this, we won't run
+    // scripts in windows with non-matching `frameId`, despite `allFrames`
+    // being set to `true`.
+    if (options.frameIds) {
+      options.allFrames = true;
+    }
+    let matcher = new WebExtensionContentScript(policy, options);
+
+    Object.assign(matcher, {
+      wantReturnValue: options.wantReturnValue,
+      removeCSS: options.removeCSS,
+      cssOrigin: options.cssOrigin,
+      jsCode: options.jsCode,
+    });
+    let script = contentScripts.get(matcher);
+
+    // Add the cssCode to the script, so that it can be converted into a cached URL.
+    await script.addCSSCode(options.cssCode);
+    delete options.cssCode;
+
+    const executeInWin = innerId => {
+      let wg = WindowGlobalChild.getByInnerWindowId(innerId);
+      if (wg?.isCurrentGlobal && script.matchesWindowGlobal(wg)) {
+        let bc = wg.browsingContext;
+
+        return {
+          frameId: bc.parent ? bc.id : 0,
+          // Disable exception reporting directly to the console
+          // in order to pass the exceptions back to the callsite.
+          promise: script.injectInto(bc.window, false),
+        };
+      }
+    };
+
+    let promisesWithFrameIds = windows.map(executeInWin).filter(obj => obj);
+
+    let result = await Promise.all(
+      promisesWithFrameIds.map(async ({ frameId, promise }) => {
+        if (!options.returnResultsWithFrameIds) {
+          return promise;
+        }
+
+        try {
+          const result = await promise;
+
+          return { frameId, result };
+        } catch (error) {
+          return { frameId, error };
+        }
+      })
+    ).catch(
+      // This is useful when we do not return results/errors with frame IDs in
+      // the promises above.
+      e => Promise.reject({ message: e.message })
+    );
+
+    try {
+      // Check if the result can be structured-cloned before sending back.
+      return Cu.cloneInto(result, this);
+    } catch (e) {
+      let path = options.jsPaths.slice(-1)[0] ?? "<anonymous code>";
+      let message = `Script '${path}' result is non-structured-clonable data`;
+      return Promise.reject({ message, fileName: path });
+    }
+  },
+};
+
+/**
+ * Child side of the ExtensionContent process actor, handles some tabs.* APIs.
+ */
+export class ExtensionContentChild extends JSProcessActorChild {
+  receiveMessage({ name, data }) {
+    if (!lazy.isContentScriptProcess) {
+      return;
+    }
+    switch (name) {
+      case "DetectLanguage":
+        return ExtensionContent.handleDetectLanguage(data);
+      case "Execute":
+        return ExtensionContent.handleActorExecute(data);
+      case "ActivateScripts":
+        return ExtensionContent.handleActivateScripts(data);
+    }
+  }
+}