From 36d22d82aa202bb199967e9512281e9a53db42c9 Mon Sep 17 00:00:00 2001
From: Daniel Baumann <daniel.baumann@progress-linux.org>
Date: Sun, 7 Apr 2024 21:33:14 +0200
Subject: Adding upstream version 115.7.0esr.

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
---
 dom/browser-element/BrowserElementChild.js         |  42 ++
 dom/browser-element/BrowserElementChildPreload.js  | 290 +++++++++
 dom/browser-element/BrowserElementParent.jsm       | 276 ++++++++
 .../BrowserElementPromptService.jsm                | 720 +++++++++++++++++++++
 dom/browser-element/components.conf                |  14 +
 dom/browser-element/moz.build                      |  37 ++
 dom/browser-element/nsIBrowserElementAPI.idl       |  44 ++
 7 files changed, 1423 insertions(+)
 create mode 100644 dom/browser-element/BrowserElementChild.js
 create mode 100644 dom/browser-element/BrowserElementChildPreload.js
 create mode 100644 dom/browser-element/BrowserElementParent.jsm
 create mode 100644 dom/browser-element/BrowserElementPromptService.jsm
 create mode 100644 dom/browser-element/components.conf
 create mode 100644 dom/browser-element/moz.build
 create mode 100644 dom/browser-element/nsIBrowserElementAPI.idl

(limited to 'dom/browser-element')

diff --git a/dom/browser-element/BrowserElementChild.js b/dom/browser-element/BrowserElementChild.js
new file mode 100644
index 0000000000..762957bcd4
--- /dev/null
+++ b/dom/browser-element/BrowserElementChild.js
@@ -0,0 +1,42 @@
+/* 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/. */
+
+/* eslint-env mozilla/frame-script */
+/* global api, CopyPasteAssistent */
+
+"use strict";
+
+function debug(msg) {
+  // dump("BrowserElementChild - " + msg + "\n");
+}
+
+var BrowserElementIsReady;
+
+debug(`Might load BE scripts: BEIR: ${BrowserElementIsReady}`);
+if (!BrowserElementIsReady) {
+  debug("Loading BE scripts");
+  if (!("BrowserElementIsPreloaded" in this)) {
+    Services.scriptloader.loadSubScript(
+      "chrome://global/content/BrowserElementChildPreload.js",
+      this
+    );
+  }
+
+  function onDestroy() {
+    removeMessageListener("browser-element-api:destroy", onDestroy);
+
+    if (api) {
+      api.destroy();
+    }
+
+    BrowserElementIsReady = false;
+  }
+  addMessageListener("browser-element-api:destroy", onDestroy);
+
+  BrowserElementIsReady = true;
+} else {
+  debug("BE already loaded, abort");
+}
+
+sendAsyncMessage("browser-element-api:call", { msg_name: "hello" });
diff --git a/dom/browser-element/BrowserElementChildPreload.js b/dom/browser-element/BrowserElementChildPreload.js
new file mode 100644
index 0000000000..1bbcf9ff05
--- /dev/null
+++ b/dom/browser-element/BrowserElementChildPreload.js
@@ -0,0 +1,290 @@
+/* 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";
+
+/* eslint-env mozilla/frame-script */
+
+function debug(msg) {
+  // dump("BrowserElementChildPreload - " + msg + "\n");
+}
+
+debug("loaded");
+
+var BrowserElementIsReady;
+
+var { BrowserElementPromptService } = ChromeUtils.import(
+  "resource://gre/modules/BrowserElementPromptService.jsm"
+);
+
+function sendAsyncMsg(msg, data) {
+  // Ensure that we don't send any messages before BrowserElementChild.js
+  // finishes loading.
+  if (!BrowserElementIsReady) {
+    return;
+  }
+
+  if (!data) {
+    data = {};
+  }
+
+  data.msg_name = msg;
+  sendAsyncMessage("browser-element-api:call", data);
+}
+
+var LISTENED_EVENTS = [
+  // This listens to unload events from our message manager, but /not/ from
+  // the |content| window.  That's because the window's unload event doesn't
+  // bubble, and we're not using a capturing listener.  If we'd used
+  // useCapture == true, we /would/ hear unload events from the window, which
+  // is not what we want!
+  { type: "unload", useCapture: false, wantsUntrusted: false },
+];
+
+/**
+ * The BrowserElementChild implements one half of <iframe mozbrowser>.
+ * (The other half is, unsurprisingly, BrowserElementParent.)
+ *
+ * This script is injected into an <iframe mozbrowser> via
+ * nsIMessageManager::LoadFrameScript().
+ *
+ * Our job here is to listen for events within this frame and bubble them up to
+ * the parent process.
+ */
+
+var global = this;
+
+function BrowserElementChild() {
+  // Maps outer window id --> weak ref to window.  Used by modal dialog code.
+  this._windowIDDict = {};
+
+  this._init();
+}
+
+BrowserElementChild.prototype = {
+  _init() {
+    debug("Starting up.");
+
+    BrowserElementPromptService.mapWindowToBrowserElementChild(content, this);
+
+    this._shuttingDown = false;
+
+    LISTENED_EVENTS.forEach(event => {
+      addEventListener(
+        event.type,
+        this,
+        event.useCapture,
+        event.wantsUntrusted
+      );
+    });
+
+    addMessageListener("browser-element-api:call", this);
+  },
+
+  /**
+   * Shut down the frame's side of the browser API.  This is called when:
+   *   - our BrowserChildGlobal starts to die
+   *   - the content is moved to frame without the browser API
+   * This is not called when the page inside |content| unloads.
+   */
+  destroy() {
+    debug("Destroying");
+    this._shuttingDown = true;
+
+    BrowserElementPromptService.unmapWindowToBrowserElementChild(content);
+
+    LISTENED_EVENTS.forEach(event => {
+      removeEventListener(
+        event.type,
+        this,
+        event.useCapture,
+        event.wantsUntrusted
+      );
+    });
+
+    removeMessageListener("browser-element-api:call", this);
+  },
+
+  handleEvent(event) {
+    switch (event.type) {
+      case "unload":
+        this.destroy(event);
+        break;
+    }
+  },
+
+  receiveMessage(message) {
+    let self = this;
+
+    let mmCalls = {
+      "unblock-modal-prompt": this._recvStopWaiting,
+    };
+
+    if (message.data.msg_name in mmCalls) {
+      return mmCalls[message.data.msg_name].apply(self, arguments);
+    }
+    return undefined;
+  },
+
+  get _windowUtils() {
+    return content.document.defaultView.windowUtils;
+  },
+
+  _tryGetInnerWindowID(win) {
+    try {
+      return win.windowGlobalChild.innerWindowId;
+    } catch (e) {
+      return null;
+    }
+  },
+
+  /**
+   * Show a modal prompt.  Called by BrowserElementPromptService.
+   */
+  showModalPrompt(win, args) {
+    args.windowID = {
+      outer: win.docShell.outerWindowID,
+      inner: this._tryGetInnerWindowID(win),
+    };
+    sendAsyncMsg("showmodalprompt", args);
+
+    let returnValue = this._waitForResult(win);
+
+    if (
+      args.promptType == "prompt" ||
+      args.promptType == "confirm" ||
+      args.promptType == "custom-prompt"
+    ) {
+      return returnValue;
+    }
+    return undefined;
+  },
+
+  /**
+   * Spin in a nested event loop until we receive a unblock-modal-prompt message for
+   * this window.
+   */
+  _waitForResult(win) {
+    debug("_waitForResult(" + win + ")");
+    let utils = win.windowUtils;
+
+    let outerWindowID = win.docShell.outerWindowID;
+    let innerWindowID = this._tryGetInnerWindowID(win);
+    if (innerWindowID === null) {
+      // I have no idea what waiting for a result means when there's no inner
+      // window, so let's just bail.
+      debug("_waitForResult: No inner window. Bailing.");
+      return undefined;
+    }
+
+    this._windowIDDict[outerWindowID] = Cu.getWeakReference(win);
+
+    debug(
+      "Entering modal state (outerWindowID=" +
+        outerWindowID +
+        ", " +
+        "innerWindowID=" +
+        innerWindowID +
+        ")"
+    );
+
+    utils.enterModalState();
+
+    // We'll decrement win.modalDepth when we receive a unblock-modal-prompt message
+    // for the window.
+    if (!win.modalDepth) {
+      win.modalDepth = 0;
+    }
+    win.modalDepth++;
+    let origModalDepth = win.modalDepth;
+
+    debug("Nested event loop - begin");
+    Services.tm.spinEventLoopUntil(
+      "BrowserElementChildPreload.js:_waitForResult",
+      () => {
+        // Bail out of the loop if the inner window changed; that means the
+        // window navigated.  Bail out when we're shutting down because otherwise
+        // we'll leak our window.
+        if (this._tryGetInnerWindowID(win) !== innerWindowID) {
+          debug(
+            "_waitForResult: Inner window ID changed " +
+              "while in nested event loop."
+          );
+          return true;
+        }
+
+        return win.modalDepth !== origModalDepth || this._shuttingDown;
+      }
+    );
+    debug("Nested event loop - finish");
+
+    if (win.modalDepth == 0) {
+      delete this._windowIDDict[outerWindowID];
+    }
+
+    // If we exited the loop because the inner window changed, then bail on the
+    // modal prompt.
+    if (innerWindowID !== this._tryGetInnerWindowID(win)) {
+      throw Components.Exception(
+        "Modal state aborted by navigation",
+        Cr.NS_ERROR_NOT_AVAILABLE
+      );
+    }
+
+    let returnValue = win.modalReturnValue;
+    delete win.modalReturnValue;
+
+    if (!this._shuttingDown) {
+      utils.leaveModalState();
+    }
+
+    debug(
+      "Leaving modal state (outerID=" +
+        outerWindowID +
+        ", " +
+        "innerID=" +
+        innerWindowID +
+        ")"
+    );
+    return returnValue;
+  },
+
+  _recvStopWaiting(msg) {
+    let outerID = msg.json.windowID.outer;
+    let innerID = msg.json.windowID.inner;
+    let returnValue = msg.json.returnValue;
+    debug(
+      "recvStopWaiting(outer=" +
+        outerID +
+        ", inner=" +
+        innerID +
+        ", returnValue=" +
+        returnValue +
+        ")"
+    );
+
+    if (!this._windowIDDict[outerID]) {
+      debug("recvStopWaiting: No record of outer window ID " + outerID);
+      return;
+    }
+
+    let win = this._windowIDDict[outerID].get();
+
+    if (!win) {
+      debug("recvStopWaiting, but window is gone\n");
+      return;
+    }
+
+    if (innerID !== this._tryGetInnerWindowID(win)) {
+      debug("recvStopWaiting, but inner ID has changed\n");
+      return;
+    }
+
+    debug("recvStopWaiting " + win);
+    win.modalReturnValue = returnValue;
+    win.modalDepth--;
+  },
+};
+
+var api = new BrowserElementChild();
diff --git a/dom/browser-element/BrowserElementParent.jsm b/dom/browser-element/BrowserElementParent.jsm
new file mode 100644
index 0000000000..ec342dace2
--- /dev/null
+++ b/dom/browser-element/BrowserElementParent.jsm
@@ -0,0 +1,276 @@
+/* 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";
+
+/* BrowserElementParent injects script to listen for certain events in the
+ * child.  We then listen to messages from the child script and take
+ * appropriate action here in the parent.
+ */
+
+const { BrowserElementPromptService } = ChromeUtils.import(
+  "resource://gre/modules/BrowserElementPromptService.jsm"
+);
+
+function debug(msg) {
+  // dump("BrowserElementParent - " + msg + "\n");
+}
+
+function handleWindowEvent(e) {
+  if (this._browserElementParents) {
+    let beps = ChromeUtils.nondeterministicGetWeakMapKeys(
+      this._browserElementParents
+    );
+    beps.forEach(bep => bep._handleOwnerEvent(e));
+  }
+}
+
+function BrowserElementParent() {
+  debug("Creating new BrowserElementParent object");
+}
+
+BrowserElementParent.prototype = {
+  classDescription: "BrowserElementAPI implementation",
+  classID: Components.ID("{9f171ac4-0939-4ef8-b360-3408aedc3060}"),
+  contractID: "@mozilla.org/dom/browser-element-api;1",
+  QueryInterface: ChromeUtils.generateQI([
+    "nsIBrowserElementAPI",
+    "nsISupportsWeakReference",
+  ]),
+
+  setFrameLoader(frameLoader) {
+    debug("Setting frameLoader");
+    this._frameLoader = frameLoader;
+    this._frameElement = frameLoader.ownerElement;
+    if (!this._frameElement) {
+      debug("No frame element?");
+      return;
+    }
+    // Listen to visibilitychange on the iframe's owner window, and forward
+    // changes down to the child.  We want to do this while registering as few
+    // visibilitychange listeners on _window as possible, because such a listener
+    // may live longer than this BrowserElementParent object.
+    //
+    // To accomplish this, we register just one listener on the window, and have
+    // it reference a WeakMap whose keys are all the BrowserElementParent objects
+    // on the window.  Then when the listener fires, we iterate over the
+    // WeakMap's keys (which we can do, because we're chrome) to notify the
+    // BrowserElementParents.
+    if (!this._window._browserElementParents) {
+      this._window._browserElementParents = new WeakMap();
+      let handler = handleWindowEvent.bind(this._window);
+      let windowEvents = ["visibilitychange"];
+      for (let event of windowEvents) {
+        Services.els.addSystemEventListener(
+          this._window,
+          event,
+          handler,
+          /* useCapture = */ true
+        );
+      }
+    }
+
+    this._window._browserElementParents.set(this, null);
+
+    // Insert ourself into the prompt service.
+    BrowserElementPromptService.mapFrameToBrowserElementParent(
+      this._frameElement,
+      this
+    );
+    this._setupMessageListener();
+  },
+
+  destroyFrameScripts() {
+    debug("Destroying frame scripts");
+    this._mm.sendAsyncMessage("browser-element-api:destroy");
+  },
+
+  _setupMessageListener() {
+    this._mm = this._frameLoader.messageManager;
+    this._mm.addMessageListener("browser-element-api:call", this);
+  },
+
+  receiveMessage(aMsg) {
+    if (!this._isAlive()) {
+      return undefined;
+    }
+
+    // Messages we receive are handed to functions which take a (data) argument,
+    // where |data| is the message manager's data object.
+    // We use a single message and dispatch to various function based
+    // on data.msg_name
+    let mmCalls = {
+      hello: this._recvHello,
+    };
+
+    let mmSecuritySensitiveCalls = {
+      showmodalprompt: this._handleShowModalPrompt,
+    };
+
+    if (aMsg.data.msg_name in mmCalls) {
+      return mmCalls[aMsg.data.msg_name].apply(this, arguments);
+    } else if (aMsg.data.msg_name in mmSecuritySensitiveCalls) {
+      return mmSecuritySensitiveCalls[aMsg.data.msg_name].apply(
+        this,
+        arguments
+      );
+    }
+    return undefined;
+  },
+
+  _removeMessageListener() {
+    this._mm.removeMessageListener("browser-element-api:call", this);
+  },
+
+  /**
+   * You shouldn't touch this._frameElement or this._window if _isAlive is
+   * false.  (You'll likely get an exception if you do.)
+   */
+  _isAlive() {
+    return (
+      !Cu.isDeadWrapper(this._frameElement) &&
+      !Cu.isDeadWrapper(this._frameElement.ownerDocument) &&
+      !Cu.isDeadWrapper(this._frameElement.ownerGlobal)
+    );
+  },
+
+  get _window() {
+    return this._frameElement.ownerGlobal;
+  },
+
+  _sendAsyncMsg(msg, data) {
+    try {
+      if (!data) {
+        data = {};
+      }
+
+      data.msg_name = msg;
+      this._mm.sendAsyncMessage("browser-element-api:call", data);
+    } catch (e) {
+      return false;
+    }
+    return true;
+  },
+
+  _recvHello() {
+    debug("recvHello");
+
+    // Inform our child if our owner element's document is invisible.  Note
+    // that we must do so here, rather than in the BrowserElementParent
+    // constructor, because the BrowserElementChild may not be initialized when
+    // we run our constructor.
+    if (this._window.document.hidden) {
+      this._ownerVisibilityChange();
+    }
+  },
+
+  /**
+   * Fire either a vanilla or a custom event, depending on the contents of
+   * |data|.
+   */
+  _fireEventFromMsg(data) {
+    let detail = data.json;
+    let name = detail.msg_name;
+
+    // For events that send a "_payload_" property, we just want to transmit
+    // this in the event.
+    if ("_payload_" in detail) {
+      detail = detail._payload_;
+    }
+
+    debug("fireEventFromMsg: " + name + ", " + JSON.stringify(detail));
+    let evt = this._createEvent(name, detail, /* cancelable = */ false);
+    this._frameElement.dispatchEvent(evt);
+  },
+
+  _handleShowModalPrompt(data) {
+    // Fire a showmodalprmopt event on the iframe.  When this method is called,
+    // the child is spinning in a nested event loop waiting for an
+    // unblock-modal-prompt message.
+    //
+    // If the embedder calls preventDefault() on the showmodalprompt event,
+    // we'll block the child until event.detail.unblock() is called.
+    //
+    // Otherwise, if preventDefault() is not called, we'll send the
+    // unblock-modal-prompt message to the child as soon as the event is done
+    // dispatching.
+
+    let detail = data.json;
+    debug("handleShowPrompt " + JSON.stringify(detail));
+
+    // Strip off the windowID property from the object we send along in the
+    // event.
+    let windowID = detail.windowID;
+    delete detail.windowID;
+    debug("Event will have detail: " + JSON.stringify(detail));
+    let evt = this._createEvent(
+      "showmodalprompt",
+      detail,
+      /* cancelable = */ true
+    );
+
+    let self = this;
+    let unblockMsgSent = false;
+    function sendUnblockMsg() {
+      if (unblockMsgSent) {
+        return;
+      }
+      unblockMsgSent = true;
+
+      // We don't need to sanitize evt.detail.returnValue (e.g. converting the
+      // return value of confirm() to a boolean); Gecko does that for us.
+
+      let data = { windowID, returnValue: evt.detail.returnValue };
+      self._sendAsyncMsg("unblock-modal-prompt", data);
+    }
+
+    Cu.exportFunction(sendUnblockMsg, evt.detail, { defineAs: "unblock" });
+
+    this._frameElement.dispatchEvent(evt);
+
+    if (!evt.defaultPrevented) {
+      // Unblock the inner frame immediately.  Otherwise we'll unblock upon
+      // evt.detail.unblock().
+      sendUnblockMsg();
+    }
+  },
+
+  _createEvent(evtName, detail, cancelable) {
+    // This will have to change if we ever want to send a CustomEvent with null
+    // detail.  For now, it's OK.
+    if (detail !== undefined && detail !== null) {
+      detail = Cu.cloneInto(detail, this._window);
+      return new this._window.CustomEvent("mozbrowser" + evtName, {
+        bubbles: true,
+        cancelable,
+        detail,
+      });
+    }
+
+    return new this._window.Event("mozbrowser" + evtName, {
+      bubbles: true,
+      cancelable,
+    });
+  },
+
+  _handleOwnerEvent(evt) {
+    switch (evt.type) {
+      case "visibilitychange":
+        this._ownerVisibilityChange();
+        break;
+    }
+  },
+
+  /**
+   * Called when the visibility of the window which owns this iframe changes.
+   */
+  _ownerVisibilityChange() {
+    let bc = this._frameLoader?.browsingContext;
+    if (bc) {
+      bc.isActive = !this._window.document.hidden;
+    }
+  },
+};
+
+var EXPORTED_SYMBOLS = ["BrowserElementParent"];
diff --git a/dom/browser-element/BrowserElementPromptService.jsm b/dom/browser-element/BrowserElementPromptService.jsm
new file mode 100644
index 0000000000..dd73004959
--- /dev/null
+++ b/dom/browser-element/BrowserElementPromptService.jsm
@@ -0,0 +1,720 @@
+/* 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/. */
+/* vim: set ft=javascript : */
+
+"use strict";
+
+var Cm = Components.manager.QueryInterface(Ci.nsIComponentRegistrar);
+
+var EXPORTED_SYMBOLS = ["BrowserElementPromptService"];
+
+function debug(msg) {
+  // dump("BrowserElementPromptService - " + msg + "\n");
+}
+
+function BrowserElementPrompt(win, browserElementChild) {
+  this._win = win;
+  this._browserElementChild = browserElementChild;
+}
+
+BrowserElementPrompt.prototype = {
+  QueryInterface: ChromeUtils.generateQI(["nsIPrompt"]),
+
+  alert(title, text) {
+    this._browserElementChild.showModalPrompt(this._win, {
+      promptType: "alert",
+      title,
+      message: text,
+      returnValue: undefined,
+    });
+  },
+
+  alertCheck(title, text, checkMsg, checkState) {
+    // Treat this like a normal alert() call, ignoring the checkState.  The
+    // front-end can do its own suppression of the alert() if it wants.
+    this.alert(title, text);
+  },
+
+  confirm(title, text) {
+    return this._browserElementChild.showModalPrompt(this._win, {
+      promptType: "confirm",
+      title,
+      message: text,
+      returnValue: undefined,
+    });
+  },
+
+  confirmCheck(title, text, checkMsg, checkState) {
+    return this.confirm(title, text);
+  },
+
+  // Each button is described by an object with the following schema
+  // {
+  //   string messageType,  // 'builtin' or 'custom'
+  //   string message, // 'ok', 'cancel', 'yes', 'no', 'save', 'dontsave',
+  //                   // 'revert' or a string from caller if messageType was 'custom'.
+  // }
+  //
+  // Expected result from embedder:
+  // {
+  //   int button, // Index of the button that user pressed.
+  //   boolean checked, // True if the check box is checked.
+  // }
+  confirmEx(
+    title,
+    text,
+    buttonFlags,
+    button0Title,
+    button1Title,
+    button2Title,
+    checkMsg,
+    checkState
+  ) {
+    let buttonProperties = this._buildConfirmExButtonProperties(
+      buttonFlags,
+      button0Title,
+      button1Title,
+      button2Title
+    );
+    let defaultReturnValue = { selectedButton: buttonProperties.defaultButton };
+    if (checkMsg) {
+      defaultReturnValue.checked = checkState.value;
+    }
+    let ret = this._browserElementChild.showModalPrompt(this._win, {
+      promptType: "custom-prompt",
+      title,
+      message: text,
+      defaultButton: buttonProperties.defaultButton,
+      buttons: buttonProperties.buttons,
+      showCheckbox: !!checkMsg,
+      checkboxMessage: checkMsg,
+      checkboxCheckedByDefault: !!checkState.value,
+      returnValue: defaultReturnValue,
+    });
+    if (checkMsg) {
+      checkState.value = ret.checked;
+    }
+    return buttonProperties.indexToButtonNumberMap[ret.selectedButton];
+  },
+
+  prompt(title, text, value, checkMsg, checkState) {
+    let rv = this._browserElementChild.showModalPrompt(this._win, {
+      promptType: "prompt",
+      title,
+      message: text,
+      initialValue: value.value,
+      returnValue: null,
+    });
+
+    value.value = rv;
+
+    // nsIPrompt::Prompt returns true if the user pressed "OK" at the prompt,
+    // and false if the user pressed "Cancel".
+    //
+    // BrowserElementChild returns null for "Cancel" and returns the string the
+    // user entered otherwise.
+    return rv !== null;
+  },
+
+  promptUsernameAndPassword(title, text, username, password) {
+    throw Components.Exception("", Cr.NS_ERROR_NOT_IMPLEMENTED);
+  },
+
+  promptPassword(title, text, password) {
+    throw Components.Exception("", Cr.NS_ERROR_NOT_IMPLEMENTED);
+  },
+
+  select(title, text, aSelectList, aOutSelection) {
+    throw Components.Exception("", Cr.NS_ERROR_NOT_IMPLEMENTED);
+  },
+
+  _buildConfirmExButtonProperties(
+    buttonFlags,
+    button0Title,
+    button1Title,
+    button2Title
+  ) {
+    let r = {
+      defaultButton: -1,
+      buttons: [],
+      // This map is for translating array index to the button number that
+      // is recognized by Gecko. This shouldn't be exposed to embedder.
+      indexToButtonNumberMap: [],
+    };
+
+    let defaultButton = 0; // Default to Button 0.
+    if (buttonFlags & Ci.nsIPrompt.BUTTON_POS_1_DEFAULT) {
+      defaultButton = 1;
+    } else if (buttonFlags & Ci.nsIPrompt.BUTTON_POS_2_DEFAULT) {
+      defaultButton = 2;
+    }
+
+    // Properties of each button.
+    let buttonPositions = [
+      Ci.nsIPrompt.BUTTON_POS_0,
+      Ci.nsIPrompt.BUTTON_POS_1,
+      Ci.nsIPrompt.BUTTON_POS_2,
+    ];
+
+    function buildButton(buttonTitle, buttonNumber) {
+      let ret = {};
+      let buttonPosition = buttonPositions[buttonNumber];
+      let mask = 0xff * buttonPosition; // 8 bit mask
+      let titleType = (buttonFlags & mask) / buttonPosition;
+
+      ret.messageType = "builtin";
+      switch (titleType) {
+        case Ci.nsIPrompt.BUTTON_TITLE_OK:
+          ret.message = "ok";
+          break;
+        case Ci.nsIPrompt.BUTTON_TITLE_CANCEL:
+          ret.message = "cancel";
+          break;
+        case Ci.nsIPrompt.BUTTON_TITLE_YES:
+          ret.message = "yes";
+          break;
+        case Ci.nsIPrompt.BUTTON_TITLE_NO:
+          ret.message = "no";
+          break;
+        case Ci.nsIPrompt.BUTTON_TITLE_SAVE:
+          ret.message = "save";
+          break;
+        case Ci.nsIPrompt.BUTTON_TITLE_DONT_SAVE:
+          ret.message = "dontsave";
+          break;
+        case Ci.nsIPrompt.BUTTON_TITLE_REVERT:
+          ret.message = "revert";
+          break;
+        case Ci.nsIPrompt.BUTTON_TITLE_IS_STRING:
+          ret.message = buttonTitle;
+          ret.messageType = "custom";
+          break;
+        default:
+          // This button is not shown.
+          return;
+      }
+
+      // If this is the default button, set r.defaultButton to
+      // the index of this button in the array. This value is going to be
+      // exposed to the embedder.
+      if (defaultButton === buttonNumber) {
+        r.defaultButton = r.buttons.length;
+      }
+      r.buttons.push(ret);
+      r.indexToButtonNumberMap.push(buttonNumber);
+    }
+
+    buildButton(button0Title, 0);
+    buildButton(button1Title, 1);
+    buildButton(button2Title, 2);
+
+    // If defaultButton is still -1 here, it means the default button won't
+    // be shown.
+    if (r.defaultButton === -1) {
+      throw new Components.Exception(
+        "Default button won't be shown",
+        Cr.NS_ERROR_FAILURE
+      );
+    }
+
+    return r;
+  },
+};
+
+function BrowserElementAuthPrompt() {}
+
+BrowserElementAuthPrompt.prototype = {
+  QueryInterface: ChromeUtils.generateQI(["nsIAuthPrompt2"]),
+
+  promptAuth: function promptAuth(channel, level, authInfo) {
+    throw Components.Exception("", Cr.NS_ERROR_NOT_IMPLEMENTED);
+  },
+
+  asyncPromptAuth: function asyncPromptAuth(
+    channel,
+    callback,
+    context,
+    level,
+    authInfo
+  ) {
+    debug("asyncPromptAuth");
+
+    // The cases that we don't support now.
+    if (
+      authInfo.flags & Ci.nsIAuthInformation.AUTH_PROXY &&
+      authInfo.flags & Ci.nsIAuthInformation.ONLY_PASSWORD
+    ) {
+      throw Components.Exception("", Cr.NS_ERROR_FAILURE);
+    }
+
+    let frame = this._getFrameFromChannel(channel);
+    if (!frame) {
+      debug("Cannot get frame, asyncPromptAuth fail");
+      throw Components.Exception("", Cr.NS_ERROR_FAILURE);
+    }
+
+    let browserElementParent =
+      BrowserElementPromptService.getBrowserElementParentForFrame(frame);
+
+    if (!browserElementParent) {
+      debug("Failed to load browser element parent.");
+      throw Components.Exception("", Cr.NS_ERROR_FAILURE);
+    }
+
+    let consumer = {
+      QueryInterface: ChromeUtils.generateQI(["nsICancelable"]),
+      callback,
+      context,
+      cancel() {
+        this.callback.onAuthCancelled(this.context, false);
+        this.callback = null;
+        this.context = null;
+      },
+    };
+
+    let [hostname, httpRealm] = this._getAuthTarget(channel, authInfo);
+    let hashKey = level + "|" + hostname + "|" + httpRealm;
+    let asyncPrompt = this._asyncPrompts[hashKey];
+    if (asyncPrompt) {
+      asyncPrompt.consumers.push(consumer);
+      return consumer;
+    }
+
+    asyncPrompt = {
+      consumers: [consumer],
+      channel,
+      authInfo,
+      level,
+      inProgress: false,
+      browserElementParent,
+    };
+
+    this._asyncPrompts[hashKey] = asyncPrompt;
+    this._doAsyncPrompt();
+    return consumer;
+  },
+
+  // Utilities for nsIAuthPrompt2 ----------------
+
+  _asyncPrompts: {},
+  _asyncPromptInProgress: new WeakMap(),
+  _doAsyncPrompt() {
+    // Find the key of a prompt whose browser element parent does not have
+    // async prompt in progress.
+    let hashKey = null;
+    for (let key in this._asyncPrompts) {
+      let prompt = this._asyncPrompts[key];
+      if (!this._asyncPromptInProgress.get(prompt.browserElementParent)) {
+        hashKey = key;
+        break;
+      }
+    }
+
+    // Didn't find an available prompt, so just return.
+    if (!hashKey) {
+      return;
+    }
+
+    let prompt = this._asyncPrompts[hashKey];
+
+    this._asyncPromptInProgress.set(prompt.browserElementParent, true);
+    prompt.inProgress = true;
+
+    let self = this;
+    let callback = function (ok, username, password) {
+      debug(
+        "Async auth callback is called, ok = " + ok + ", username = " + username
+      );
+
+      // Here we got the username and password provided by embedder, or
+      // ok = false if the prompt was cancelled by embedder.
+      delete self._asyncPrompts[hashKey];
+      prompt.inProgress = false;
+      self._asyncPromptInProgress.delete(prompt.browserElementParent);
+
+      // Fill authentication information with username and password provided
+      // by user.
+      let flags = prompt.authInfo.flags;
+      if (username) {
+        if (flags & Ci.nsIAuthInformation.NEED_DOMAIN) {
+          // Domain is separated from username by a backslash
+          let idx = username.indexOf("\\");
+          if (idx == -1) {
+            prompt.authInfo.username = username;
+          } else {
+            prompt.authInfo.domain = username.substring(0, idx);
+            prompt.authInfo.username = username.substring(idx + 1);
+          }
+        } else {
+          prompt.authInfo.username = username;
+        }
+      }
+
+      if (password) {
+        prompt.authInfo.password = password;
+      }
+
+      for (let consumer of prompt.consumers) {
+        if (!consumer.callback) {
+          // Not having a callback means that consumer didn't provide it
+          // or canceled the notification.
+          continue;
+        }
+
+        try {
+          if (ok) {
+            debug("Ok, calling onAuthAvailable to finish auth");
+            consumer.callback.onAuthAvailable(
+              consumer.context,
+              prompt.authInfo
+            );
+          } else {
+            debug("Cancelled, calling onAuthCancelled to finish auth.");
+            consumer.callback.onAuthCancelled(consumer.context, true);
+          }
+        } catch (e) {
+          /* Throw away exceptions caused by callback */
+        }
+      }
+
+      // Process the next prompt, if one is pending.
+      self._doAsyncPrompt();
+    };
+
+    let runnable = {
+      run() {
+        // Call promptAuth of browserElementParent, to show the prompt.
+        prompt.browserElementParent.promptAuth(
+          self._createAuthDetail(prompt.channel, prompt.authInfo),
+          callback
+        );
+      },
+    };
+
+    Services.tm.dispatchToMainThread(runnable);
+  },
+
+  _getFrameFromChannel(channel) {
+    let loadContext = channel.notificationCallbacks.getInterface(
+      Ci.nsILoadContext
+    );
+    return loadContext.topFrameElement;
+  },
+
+  _createAuthDetail(channel, authInfo) {
+    let [hostname, httpRealm] = this._getAuthTarget(channel, authInfo);
+    return {
+      host: hostname,
+      path: channel.URI.pathQueryRef,
+      realm: httpRealm,
+      username: authInfo.username,
+      isProxy: !!(authInfo.flags & Ci.nsIAuthInformation.AUTH_PROXY),
+      isOnlyPassword: !!(authInfo.flags & Ci.nsIAuthInformation.ONLY_PASSWORD),
+    };
+  },
+
+  // The code is taken from nsLoginManagerPrompter.js, with slight
+  // modification for parameter name consistency here.
+  _getAuthTarget(channel, authInfo) {
+    let hostname, realm;
+
+    // If our proxy is demanding authentication, don't use the
+    // channel's actual destination.
+    if (authInfo.flags & Ci.nsIAuthInformation.AUTH_PROXY) {
+      if (!(channel instanceof Ci.nsIProxiedChannel)) {
+        throw new Error("proxy auth needs nsIProxiedChannel");
+      }
+
+      let info = channel.proxyInfo;
+      if (!info) {
+        throw new Error("proxy auth needs nsIProxyInfo");
+      }
+
+      // Proxies don't have a scheme, but we'll use "moz-proxy://"
+      // so that it's more obvious what the login is for.
+      var idnService = Cc["@mozilla.org/network/idn-service;1"].getService(
+        Ci.nsIIDNService
+      );
+      hostname =
+        "moz-proxy://" +
+        idnService.convertUTF8toACE(info.host) +
+        ":" +
+        info.port;
+      realm = authInfo.realm;
+      if (!realm) {
+        realm = hostname;
+      }
+
+      return [hostname, realm];
+    }
+
+    hostname = this._getFormattedHostname(channel.URI);
+
+    // If a HTTP WWW-Authenticate header specified a realm, that value
+    // will be available here. If it wasn't set or wasn't HTTP, we'll use
+    // the formatted hostname instead.
+    realm = authInfo.realm;
+    if (!realm) {
+      realm = hostname;
+    }
+
+    return [hostname, realm];
+  },
+
+  /**
+   * Strip out things like userPass and path for display.
+   */
+  _getFormattedHostname(uri) {
+    return uri.scheme + "://" + uri.hostPort;
+  },
+};
+
+function AuthPromptWrapper(oldImpl, browserElementImpl) {
+  this._oldImpl = oldImpl;
+  this._browserElementImpl = browserElementImpl;
+}
+
+AuthPromptWrapper.prototype = {
+  QueryInterface: ChromeUtils.generateQI(["nsIAuthPrompt2"]),
+  promptAuth(channel, level, authInfo) {
+    if (this._canGetParentElement(channel)) {
+      return this._browserElementImpl.promptAuth(channel, level, authInfo);
+    }
+    return this._oldImpl.promptAuth(channel, level, authInfo);
+  },
+
+  asyncPromptAuth(channel, callback, context, level, authInfo) {
+    if (this._canGetParentElement(channel)) {
+      return this._browserElementImpl.asyncPromptAuth(
+        channel,
+        callback,
+        context,
+        level,
+        authInfo
+      );
+    }
+    return this._oldImpl.asyncPromptAuth(
+      channel,
+      callback,
+      context,
+      level,
+      authInfo
+    );
+  },
+
+  _canGetParentElement(channel) {
+    try {
+      let context = channel.notificationCallbacks.getInterface(
+        Ci.nsILoadContext
+      );
+      let frame = context.topFrameElement;
+      if (!frame) {
+        return false;
+      }
+
+      if (!BrowserElementPromptService.getBrowserElementParentForFrame(frame)) {
+        return false;
+      }
+
+      return true;
+    } catch (e) {
+      return false;
+    }
+  },
+};
+
+function BrowserElementPromptFactory(toWrap) {
+  this._wrapped = toWrap;
+}
+
+BrowserElementPromptFactory.prototype = {
+  classID: Components.ID("{24f3d0cf-e417-4b85-9017-c9ecf8bb1299}"),
+  QueryInterface: ChromeUtils.generateQI(["nsIPromptFactory"]),
+
+  _mayUseNativePrompt() {
+    try {
+      return Services.prefs.getBoolPref("browser.prompt.allowNative");
+    } catch (e) {
+      // This properity is default to true.
+      return true;
+    }
+  },
+
+  _getNativePromptIfAllowed(win, iid, err) {
+    if (this._mayUseNativePrompt()) {
+      return this._wrapped.getPrompt(win, iid);
+    }
+
+    // Not allowed, throw an exception.
+    throw err;
+  },
+
+  getPrompt(win, iid) {
+    // It is possible for some object to get a prompt without passing
+    // valid reference of window, like nsNSSComponent. In such case, we
+    // should just fall back to the native prompt service
+    if (!win) {
+      return this._getNativePromptIfAllowed(win, iid, Cr.NS_ERROR_INVALID_ARG);
+    }
+
+    if (
+      iid.number != Ci.nsIPrompt.number &&
+      iid.number != Ci.nsIAuthPrompt2.number
+    ) {
+      debug(
+        "We don't recognize the requested IID (" +
+          iid +
+          ", " +
+          "allowed IID: " +
+          "nsIPrompt=" +
+          Ci.nsIPrompt +
+          ", " +
+          "nsIAuthPrompt2=" +
+          Ci.nsIAuthPrompt2 +
+          ")"
+      );
+      return this._getNativePromptIfAllowed(win, iid, Cr.NS_ERROR_INVALID_ARG);
+    }
+
+    // Try to find a BrowserElementChild for the window.
+    let browserElementChild =
+      BrowserElementPromptService.getBrowserElementChildForWindow(win);
+
+    if (iid.number === Ci.nsIAuthPrompt2.number) {
+      debug("Caller requests an instance of nsIAuthPrompt2.");
+
+      if (browserElementChild) {
+        // If we are able to get a BrowserElementChild, it means that
+        // the auth prompt is for a mozbrowser. Therefore we don't need to
+        // fall back.
+        return new BrowserElementAuthPrompt().QueryInterface(iid);
+      }
+
+      // Because nsIAuthPrompt2 is called in parent process. If caller
+      // wants nsIAuthPrompt2 and we cannot get BrowserElementchild,
+      // it doesn't mean that we should fallback. It is possible that we can
+      // get the BrowserElementParent from nsIChannel that passed to
+      // functions of nsIAuthPrompt2.
+      if (this._mayUseNativePrompt()) {
+        return new AuthPromptWrapper(
+          this._wrapped.getPrompt(win, iid),
+          new BrowserElementAuthPrompt().QueryInterface(iid)
+        ).QueryInterface(iid);
+      }
+      // Falling back is not allowed, so we don't need wrap the
+      // BrowserElementPrompt.
+      return new BrowserElementAuthPrompt().QueryInterface(iid);
+    }
+
+    if (!browserElementChild) {
+      debug(
+        "We can't find a browserElementChild for " + win + ", " + win.location
+      );
+      return this._getNativePromptIfAllowed(win, iid, Cr.NS_ERROR_FAILURE);
+    }
+
+    debug("Returning wrapped getPrompt for " + win);
+    return new BrowserElementPrompt(win, browserElementChild).QueryInterface(
+      iid
+    );
+  },
+};
+
+var BrowserElementPromptService = {
+  QueryInterface: ChromeUtils.generateQI([
+    "nsIObserver",
+    "nsISupportsWeakReference",
+  ]),
+
+  _initialized: false,
+
+  _init() {
+    if (this._initialized) {
+      return;
+    }
+
+    this._initialized = true;
+    this._browserElementParentMap = new WeakMap();
+
+    Services.obs.addObserver(
+      this,
+      "outer-window-destroyed",
+      /* ownsWeak = */ true
+    );
+
+    // Wrap the existing @mozilla.org/prompter;1 implementation.
+    var contractID = "@mozilla.org/prompter;1";
+    var oldCID = Cm.contractIDToCID(contractID);
+    var newCID = BrowserElementPromptFactory.prototype.classID;
+    var oldFactory = Cm.getClassObject(Cc[contractID], Ci.nsIFactory);
+
+    if (oldCID == newCID) {
+      debug("WARNING: Wrapped prompt factory is already installed!");
+      return;
+    }
+
+    var oldInstance = oldFactory.createInstance(null, Ci.nsIPromptFactory);
+    var newInstance = new BrowserElementPromptFactory(oldInstance);
+
+    var newFactory = {
+      createInstance(iid) {
+        return newInstance.QueryInterface(iid);
+      },
+    };
+    Cm.registerFactory(
+      newCID,
+      "BrowserElementPromptService's prompter;1 wrapper",
+      contractID,
+      newFactory
+    );
+
+    debug("Done installing new prompt factory.");
+  },
+
+  _getOuterWindowID(win) {
+    return win.docShell.outerWindowID;
+  },
+
+  _browserElementChildMap: {},
+  mapWindowToBrowserElementChild(win, browserElementChild) {
+    this._browserElementChildMap[this._getOuterWindowID(win)] =
+      browserElementChild;
+  },
+  unmapWindowToBrowserElementChild(win) {
+    delete this._browserElementChildMap[this._getOuterWindowID(win)];
+  },
+
+  getBrowserElementChildForWindow(win) {
+    // We only have a mapping for <iframe mozbrowser>s, not their inner
+    // <iframes>, so we look up win.top below.  window.top (when called from
+    // script) respects <iframe mozbrowser> boundaries.
+    return this._browserElementChildMap[this._getOuterWindowID(win.top)];
+  },
+
+  mapFrameToBrowserElementParent(frame, browserElementParent) {
+    this._browserElementParentMap.set(frame, browserElementParent);
+  },
+
+  getBrowserElementParentForFrame(frame) {
+    return this._browserElementParentMap.get(frame);
+  },
+
+  _observeOuterWindowDestroyed(outerWindowID) {
+    let id = outerWindowID.QueryInterface(Ci.nsISupportsPRUint64).data;
+    debug("observeOuterWindowDestroyed " + id);
+    delete this._browserElementChildMap[outerWindowID.data];
+  },
+
+  observe(subject, topic, data) {
+    switch (topic) {
+      case "outer-window-destroyed":
+        this._observeOuterWindowDestroyed(subject);
+        break;
+      default:
+        debug("Observed unexpected topic " + topic);
+    }
+  },
+};
+
+BrowserElementPromptService._init();
diff --git a/dom/browser-element/components.conf b/dom/browser-element/components.conf
new file mode 100644
index 0000000000..a29f7dc66a
--- /dev/null
+++ b/dom/browser-element/components.conf
@@ -0,0 +1,14 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# 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/.
+
+Classes = [
+    {
+        'cid': '{9f171ac4-0939-4ef8-b360-3408aedc3060}',
+        'contract_ids': ['@mozilla.org/dom/browser-element-api;1'],
+        'jsm': 'resource://gre/modules/BrowserElementParent.jsm',
+        'constructor': 'BrowserElementParent',
+    },
+]
diff --git a/dom/browser-element/moz.build b/dom/browser-element/moz.build
new file mode 100644
index 0000000000..1f83fbd436
--- /dev/null
+++ b/dom/browser-element/moz.build
@@ -0,0 +1,37 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# 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/.
+
+with Files("**"):
+    BUG_COMPONENT = ("Core", "DOM: Core & HTML")
+
+XPIDL_SOURCES += [
+    "nsIBrowserElementAPI.idl",
+]
+
+XPIDL_MODULE = "browser-element"
+
+EXTRA_JS_MODULES += [
+    "BrowserElementParent.jsm",
+    "BrowserElementPromptService.jsm",
+]
+
+XPCOM_MANIFESTS += [
+    "components.conf",
+]
+
+LOCAL_INCLUDES += [
+    "/dom/html",
+]
+
+include("/ipc/chromium/chromium-config.mozbuild")
+
+FINAL_LIBRARY = "xul"
+
+LOCAL_INCLUDES += [
+    "/dom/",
+    "/dom/base",
+    "/dom/ipc",
+]
diff --git a/dom/browser-element/nsIBrowserElementAPI.idl b/dom/browser-element/nsIBrowserElementAPI.idl
new file mode 100644
index 0000000000..4aeba96be8
--- /dev/null
+++ b/dom/browser-element/nsIBrowserElementAPI.idl
@@ -0,0 +1,44 @@
+/* -*- Mode: IDL; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=2 et sw=2 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/. */
+
+#include "nsISupports.idl"
+
+webidl FrameLoader;
+
+%{C++
+#define BROWSER_ELEMENT_API_CONTRACTID "@mozilla.org/dom/browser-element-api;1"
+#define BROWSER_ELEMENT_API_CID                                 \
+    { 0x651db7e3, 0x1734, 0x4536,                               \
+      { 0xb1, 0x5a, 0x5b, 0x3a, 0xe6, 0x44, 0x13, 0x4c } }
+%}
+
+/**
+ * Interface to the BrowserElementParent implementation. All methods
+ * but setFrameLoader throw when the remote process is dead.
+ */
+[scriptable, uuid(57758c10-6036-11e5-a837-0800200c9a66)]
+interface nsIBrowserElementAPI : nsISupports
+{
+  /**
+   * Notify frame scripts that support the API to destroy.
+   */
+  void destroyFrameScripts();
+
+  void setFrameLoader(in FrameLoader frameLoader);
+
+  void sendMouseEvent(in AString type,
+                      in uint32_t x,
+                      in uint32_t y,
+                      in uint32_t button,
+                      in uint32_t clickCount,
+                      in uint32_t mifiers);
+  void goBack();
+  void goForward();
+  void reload(in boolean hardReload);
+  void stop();
+  Promise getCanGoBack();
+  Promise getCanGoForward();
+};
-- 
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