Adding upstream version 115.8.0esr.upstream/115.8.0esr

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

1 files changed, 918 insertions, 0 deletions

diff --git a/accessible/tests/browser/shared-head.js b/accessible/tests/browser/shared-head.js
new file mode 100644
index 0000000000..9037802728
--- /dev/null
+++ b/accessible/tests/browser/shared-head.js
@@ -0,0 +1,918 @@
+/* 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";
+
+/* import-globals-from ../mochitest/common.js */
+/* import-globals-from ../mochitest/layout.js */
+/* import-globals-from ../mochitest/promisified-events.js */
+
+/* exported Logger, MOCHITESTS_DIR, invokeSetAttribute, invokeFocus,
+            invokeSetStyle, getAccessibleDOMNodeID, getAccessibleTagName,
+            addAccessibleTask, findAccessibleChildByID, isDefunct,
+            CURRENT_CONTENT_DIR, loadScripts, loadContentScripts, snippetToURL,
+            Cc, Cu, arrayFromChildren, forceGC, contentSpawnMutation,
+            DEFAULT_IFRAME_ID, DEFAULT_IFRAME_DOC_BODY_ID, invokeContentTask,
+            matchContentDoc, currentContentDoc, getContentDPR,
+            waitForImageMap, getContentBoundsForDOMElm, untilCacheIs, untilCacheOk, testBoundsWithContent, waitForContentPaint */
+
+const CURRENT_FILE_DIR = "/browser/accessible/tests/browser/";
+
+/**
+ * Current browser test directory path used to load subscripts.
+ */
+const CURRENT_DIR = `chrome://mochitests/content${CURRENT_FILE_DIR}`;
+/**
+ * A11y mochitest directory where we find common files used in both browser and
+ * plain tests.
+ */
+const MOCHITESTS_DIR =
+  "chrome://mochitests/content/a11y/accessible/tests/mochitest/";
+/**
+ * A base URL for test files used in content.
+ */
+// eslint-disable-next-line @microsoft/sdl/no-insecure-url
+const CURRENT_CONTENT_DIR = `http://example.com${CURRENT_FILE_DIR}`;
+
+const LOADED_CONTENT_SCRIPTS = new Map();
+
+const DEFAULT_CONTENT_DOC_BODY_ID = "body";
+const DEFAULT_IFRAME_ID = "default-iframe-id";
+const DEFAULT_IFRAME_DOC_BODY_ID = "default-iframe-body-id";
+
+const HTML_MIME_TYPE = "text/html";
+const XHTML_MIME_TYPE = "application/xhtml+xml";
+
+function loadHTMLFromFile(path) {
+  // Load the HTML to return in the response from file.
+  // Since it's relative to the cwd of the test runner, we start there and
+  // append to get to the actual path of the file.
+  const testHTMLFile = Services.dirsvc.get("CurWorkD", Ci.nsIFile);
+  const dirs = path.split("/");
+  for (let i = 0; i < dirs.length; i++) {
+    testHTMLFile.append(dirs[i]);
+  }
+
+  const testHTMLFileStream = Cc[
+    "@mozilla.org/network/file-input-stream;1"
+  ].createInstance(Ci.nsIFileInputStream);
+  testHTMLFileStream.init(testHTMLFile, -1, 0, 0);
+  const testHTML = NetUtil.readInputStreamToString(
+    testHTMLFileStream,
+    testHTMLFileStream.available()
+  );
+
+  return testHTML;
+}
+
+let gIsIframe = false;
+let gIsRemoteIframe = false;
+
+function currentContentDoc() {
+  return gIsIframe ? DEFAULT_IFRAME_DOC_BODY_ID : DEFAULT_CONTENT_DOC_BODY_ID;
+}
+
+/**
+ * Accessible event match criteria based on the id of the current document
+ * accessible in test.
+ *
+ * @param   {nsIAccessibleEvent}  event
+ *        Accessible event to be tested for a match.
+ *
+ * @return  {Boolean}
+ *          True if accessible event's accessible object ID matches current
+ *          document accessible ID.
+ */
+function matchContentDoc(event) {
+  return getAccessibleDOMNodeID(event.accessible) === currentContentDoc();
+}
+
+/**
+ * Used to dump debug information.
+ */
+let Logger = {
+  /**
+   * Set up this variable to dump log messages into console.
+   */
+  dumpToConsole: false,
+
+  /**
+   * Set up this variable to dump log messages into error console.
+   */
+  dumpToAppConsole: false,
+
+  /**
+   * Return true if dump is enabled.
+   */
+  get enabled() {
+    return this.dumpToConsole || this.dumpToAppConsole;
+  },
+
+  /**
+   * Dump information into console if applicable.
+   */
+  log(msg) {
+    if (this.enabled) {
+      this.logToConsole(msg);
+      this.logToAppConsole(msg);
+    }
+  },
+
+  /**
+   * Log message to console.
+   */
+  logToConsole(msg) {
+    if (this.dumpToConsole) {
+      dump(`\n${msg}\n`);
+    }
+  },
+
+  /**
+   * Log message to error console.
+   */
+  logToAppConsole(msg) {
+    if (this.dumpToAppConsole) {
+      Services.console.logStringMessage(`${msg}`);
+    }
+  },
+};
+
+/**
+ * Asynchronously set or remove content element's attribute (in content process
+ * if e10s is enabled).
+ * @param  {Object}  browser  current "tabbrowser" element
+ * @param  {String}  id       content element id
+ * @param  {String}  attr     attribute name
+ * @param  {String?} value    optional attribute value, if not present, remove
+ *                            attribute
+ * @return {Promise}          promise indicating that attribute is set/removed
+ */
+function invokeSetAttribute(browser, id, attr, value) {
+  if (value) {
+    Logger.log(`Setting ${attr} attribute to ${value} for node with id: ${id}`);
+  } else {
+    Logger.log(`Removing ${attr} attribute from node with id: ${id}`);
+  }
+
+  return invokeContentTask(
+    browser,
+    [id, attr, value],
+    (contentId, contentAttr, contentValue) => {
+      let elm = content.document.getElementById(contentId);
+      if (contentValue) {
+        elm.setAttribute(contentAttr, contentValue);
+      } else {
+        elm.removeAttribute(contentAttr);
+      }
+    }
+  );
+}
+
+/**
+ * Asynchronously set or remove content element's style (in content process if
+ * e10s is enabled, or in fission process if fission is enabled and a fission
+ * frame is present).
+ * @param  {Object}  browser  current "tabbrowser" element
+ * @param  {String}  id       content element id
+ * @param  {String}  aStyle   style property name
+ * @param  {String?} aValue   optional style property value, if not present,
+ *                            remove style
+ * @return {Promise}          promise indicating that style is set/removed
+ */
+function invokeSetStyle(browser, id, style, value) {
+  if (value) {
+    Logger.log(`Setting ${style} style to ${value} for node with id: ${id}`);
+  } else {
+    Logger.log(`Removing ${style} style from node with id: ${id}`);
+  }
+
+  return invokeContentTask(
+    browser,
+    [id, style, value],
+    (contentId, contentStyle, contentValue) => {
+      const elm = content.document.getElementById(contentId);
+      if (contentValue) {
+        elm.style[contentStyle] = contentValue;
+      } else {
+        delete elm.style[contentStyle];
+      }
+    }
+  );
+}
+
+/**
+ * Asynchronously set focus on a content element (in content process if e10s is
+ * enabled, or in fission process if fission is enabled and a fission frame is
+ * present).
+ * @param  {Object}  browser  current "tabbrowser" element
+ * @param  {String}  id       content element id
+ * @return {Promise} promise  indicating that focus is set
+ */
+function invokeFocus(browser, id) {
+  Logger.log(`Setting focus on a node with id: ${id}`);
+
+  return invokeContentTask(browser, [id], contentId => {
+    const elm = content.document.getElementById(contentId);
+    if (elm.editor) {
+      elm.selectionStart = elm.selectionEnd = elm.value.length;
+    }
+
+    elm.focus();
+  });
+}
+
+/**
+ * Get DPR for a specific content window.
+ * @param  browser
+ *         Browser for which we want its content window's DPR reported.
+ *
+ * @return {Promise}
+ *         Promise with the value that resolves to the devicePixelRatio of the
+ *         content window of a given browser.
+ *
+ */
+function getContentDPR(browser) {
+  return invokeContentTask(browser, [], () => content.window.devicePixelRatio);
+}
+
+/**
+ * Asynchronously perform a task in content (in content process if e10s is
+ * enabled, or in fission process if fission is enabled and a fission frame is
+ * present).
+ * @param  {Object}    browser  current "tabbrowser" element
+ * @param  {Array}     args     arguments for the content task
+ * @param  {Function}  task     content task function
+ *
+ * @return {Promise} promise  indicating that content task is complete
+ */
+function invokeContentTask(browser, args, task) {
+  return SpecialPowers.spawn(
+    browser,
+    [DEFAULT_IFRAME_ID, task.toString(), ...args],
+    (iframeId, contentTask, ...contentArgs) => {
+      // eslint-disable-next-line no-eval
+      const runnableTask = eval(`
+      (() => {
+        return (${contentTask});
+      })();`);
+      const frame = content.document.getElementById(iframeId);
+
+      return frame
+        ? SpecialPowers.spawn(frame, contentArgs, runnableTask)
+        : runnableTask.call(this, ...contentArgs);
+    }
+  );
+}
+
+/**
+ * Compare process ID's between the top level content process and possible
+ * remote/local iframe proccess.
+ * @param {Object}  browser
+ *        Top level browser object for a tab.
+ * @param {Boolean} isRemote
+ *        Indicates if we expect the iframe content process to be remote or not.
+ */
+async function comparePIDs(browser, isRemote) {
+  function getProcessID() {
+    return Services.appinfo.processID;
+  }
+
+  const contentPID = await SpecialPowers.spawn(browser, [], getProcessID);
+  const iframePID = await invokeContentTask(browser, [], getProcessID);
+  is(
+    isRemote,
+    contentPID !== iframePID,
+    isRemote
+      ? "Remote IFRAME is in a different process."
+      : "IFRAME is in the same process."
+  );
+}
+
+/**
+ * Load a list of scripts into the test
+ * @param {Array} scripts  a list of scripts to load
+ */
+function loadScripts(...scripts) {
+  for (let script of scripts) {
+    let path =
+      typeof script === "string"
+        ? `${CURRENT_DIR}${script}`
+        : `${script.dir}${script.name}`;
+    Services.scriptloader.loadSubScript(path, this);
+  }
+}
+
+/**
+ * Load a list of scripts into target's content.
+ * @param {Object} target
+ *        target for loading scripts into
+ * @param {Array}  scripts
+ *        a list of scripts to load into content
+ */
+async function loadContentScripts(target, ...scripts) {
+  for (let { script, symbol } of scripts) {
+    let contentScript = `${CURRENT_DIR}${script}`;
+    let loadedScriptSet = LOADED_CONTENT_SCRIPTS.get(contentScript);
+    if (!loadedScriptSet) {
+      loadedScriptSet = new WeakSet();
+      LOADED_CONTENT_SCRIPTS.set(contentScript, loadedScriptSet);
+    } else if (loadedScriptSet.has(target)) {
+      continue;
+    }
+
+    await SpecialPowers.spawn(
+      target,
+      [contentScript, symbol],
+      async (_contentScript, importSymbol) => {
+        let module = ChromeUtils.importESModule(_contentScript);
+        content.window[importSymbol] = module[importSymbol];
+      }
+    );
+    loadedScriptSet.add(target);
+  }
+}
+
+function attrsToString(attrs) {
+  return Object.entries(attrs)
+    .map(([attr, value]) => `${attr}=${JSON.stringify(value)}`)
+    .join(" ");
+}
+
+function wrapWithIFrame(doc, options = {}) {
+  let src;
+  let { iframeAttrs = {}, iframeDocBodyAttrs = {} } = options;
+  iframeDocBodyAttrs = {
+    id: DEFAULT_IFRAME_DOC_BODY_ID,
+    ...iframeDocBodyAttrs,
+  };
+  if (options.remoteIframe) {
+    // eslint-disable-next-line @microsoft/sdl/no-insecure-url
+    const srcURL = new URL(`http://example.net/document-builder.sjs`);
+    if (doc.endsWith("html")) {
+      srcURL.searchParams.append("file", `${CURRENT_FILE_DIR}${doc}`);
+    } else {
+      srcURL.searchParams.append(
+        "html",
+        `<!doctype html>
+        <html>
+          <head>
+            <meta charset="utf-8"/>
+            <title>Accessibility Fission Test</title>
+          </head>
+          <body ${attrsToString(iframeDocBodyAttrs)}>${doc}</body>
+        </html>`
+      );
+    }
+    src = srcURL.href;
+  } else {
+    const mimeType = doc.endsWith("xhtml") ? XHTML_MIME_TYPE : HTML_MIME_TYPE;
+    if (doc.endsWith("html")) {
+      doc = loadHTMLFromFile(`${CURRENT_FILE_DIR}${doc}`);
+      doc = doc.replace(
+        /<body[.\s\S]*?>/,
+        `<body ${attrsToString(iframeDocBodyAttrs)}>`
+      );
+    } else {
+      doc = `<!doctype html>
+      <body ${attrsToString(iframeDocBodyAttrs)}>${doc}</body>`;
+    }
+
+    src = `data:${mimeType};charset=utf-8,${encodeURIComponent(doc)}`;
+  }
+
+  iframeAttrs = {
+    id: DEFAULT_IFRAME_ID,
+    src,
+    ...iframeAttrs,
+  };
+
+  return `<iframe ${attrsToString(iframeAttrs)}/>`;
+}
+
+/**
+ * Takes an HTML snippet or HTML doc url and returns an encoded URI for a full
+ * document with the snippet or the URL as a source for the IFRAME.
+ * @param {String} doc
+ *        a markup snippet or url.
+ * @param {Object} options (see options in addAccessibleTask).
+ *
+ * @return {String}
+ *        a base64 encoded data url of the document container the snippet.
+ **/
+function snippetToURL(doc, options = {}) {
+  const { contentDocBodyAttrs = {} } = options;
+  const attrs = {
+    id: DEFAULT_CONTENT_DOC_BODY_ID,
+    ...contentDocBodyAttrs,
+  };
+
+  if (gIsIframe) {
+    doc = wrapWithIFrame(doc, options);
+  }
+
+  const encodedDoc = encodeURIComponent(
+    `<!doctype html>
+    <html>
+      <head>
+        <meta charset="utf-8"/>
+        <title>Accessibility Test</title>
+      </head>
+      <body ${attrsToString(attrs)}>${doc}</body>
+    </html>`
+  );
+
+  return `data:text/html;charset=utf-8,${encodedDoc}`;
+}
+
+function accessibleTask(doc, task, options = {}) {
+  return async function () {
+    gIsRemoteIframe = options.remoteIframe;
+    gIsIframe = options.iframe || gIsRemoteIframe;
+    let url;
+    if (options.chrome && doc.endsWith("html")) {
+      // Load with a chrome:// URL so this loads as a chrome document in the
+      // parent process.
+      url = `${CURRENT_DIR}${doc}`;
+    } else if (doc.endsWith("html") && !gIsIframe) {
+      url = `${CURRENT_CONTENT_DIR}${doc}`;
+    } else {
+      url = snippetToURL(doc, options);
+    }
+
+    registerCleanupFunction(() => {
+      for (let observer of Services.obs.enumerateObservers(
+        "accessible-event"
+      )) {
+        Services.obs.removeObserver(observer, "accessible-event");
+      }
+    });
+
+    let onContentDocLoad;
+    if (!options.chrome) {
+      onContentDocLoad = waitForEvent(
+        EVENT_DOCUMENT_LOAD_COMPLETE,
+        DEFAULT_CONTENT_DOC_BODY_ID
+      );
+    }
+
+    let onIframeDocLoad;
+    if (options.remoteIframe && !options.skipFissionDocLoad) {
+      onIframeDocLoad = waitForEvent(
+        EVENT_DOCUMENT_LOAD_COMPLETE,
+        DEFAULT_IFRAME_DOC_BODY_ID
+      );
+    }
+
+    await BrowserTestUtils.withNewTab(
+      {
+        gBrowser,
+        // For chrome, we need a non-remote browser.
+        opening: !options.chrome
+          ? url
+          : () => {
+              // Passing forceNotRemote: true still sets maychangeremoteness,
+              // which will cause data: URIs to load remotely. There's no way to
+              // avoid this with gBrowser or BrowserTestUtils. Therefore, we
+              // load a blank document initially and replace it below.
+              gBrowser.selectedTab = BrowserTestUtils.addTab(
+                gBrowser,
+                "about:blank",
+                {
+                  forceNotRemote: true,
+                }
+              );
+            },
+      },
+      async function (browser) {
+        registerCleanupFunction(() => {
+          if (browser) {
+            let tab = gBrowser.getTabForBrowser(browser);
+            if (tab && !tab.closing && tab.linkedBrowser) {
+              gBrowser.removeTab(tab);
+            }
+          }
+        });
+
+        if (options.chrome) {
+          await SpecialPowers.pushPrefEnv({
+            set: [["security.allow_unsafe_parent_loads", true]],
+          });
+          // Ensure this never becomes a remote browser.
+          browser.removeAttribute("maychangeremoteness");
+          // Now we can load our page without it becoming remote.
+          browser.setAttribute("src", url);
+        }
+
+        await SimpleTest.promiseFocus(browser);
+
+        if (options.chrome) {
+          ok(!browser.isRemoteBrowser, "Not remote browser");
+        } else if (Services.appinfo.browserTabsRemoteAutostart) {
+          ok(browser.isRemoteBrowser, "Actually remote browser");
+        }
+
+        let docAccessible;
+        if (options.chrome) {
+          // Chrome documents don't fire DOCUMENT_LOAD_COMPLETE. Instead, wait
+          // until we can get the DocAccessible and it doesn't have the busy
+          // state.
+          await BrowserTestUtils.waitForCondition(() => {
+            docAccessible = getAccessible(browser.contentWindow.document);
+            if (!docAccessible) {
+              return false;
+            }
+            const state = {};
+            docAccessible.getState(state, {});
+            return !(state.value & STATE_BUSY);
+          });
+        } else {
+          ({ accessible: docAccessible } = await onContentDocLoad);
+        }
+        let iframeDocAccessible;
+        if (gIsIframe) {
+          if (!options.skipFissionDocLoad) {
+            await comparePIDs(browser, options.remoteIframe);
+            iframeDocAccessible = onIframeDocLoad
+              ? (await onIframeDocLoad).accessible
+              : findAccessibleChildByID(docAccessible, DEFAULT_IFRAME_ID)
+                  .firstChild;
+          }
+        }
+
+        await loadContentScripts(browser, {
+          script: "Common.sys.mjs",
+          symbol: "CommonUtils",
+        });
+
+        await task(
+          browser,
+          iframeDocAccessible || docAccessible,
+          iframeDocAccessible && docAccessible
+        );
+      }
+    );
+  };
+}
+
+/**
+ * A wrapper around browser test add_task that triggers an accessible test task
+ * as a new browser test task with given document, data URL or markup snippet.
+ * @param  {String} doc
+ *         URL (relative to current directory) or data URL or markup snippet
+ *         that is used to test content with
+ * @param  {Function|AsyncFunction} task
+ *         a generator or a function with tests to run
+ * @param  {null|Object} options
+ *         Options for running accessibility test tasks:
+ *         - {Boolean} topLevel
+ *           Flag to run the test with content in the top level content process.
+ *           Default is true.
+ *         - {Boolean} chrome
+ *           Flag to run the test with content as a chrome document in the
+ *           parent process. Default is false. Although url can be a markup
+ *           snippet, a snippet cannot be used for XUL content. To load XUL,
+ *           specify a relative URL to a XUL document. In that case, toplevel
+ *           should usually be set to false, since XUL documents don't work in
+ *           content processes.
+ *         - {Boolean} iframe
+ *           Flag to run the test with content wrapped in an iframe. Default is
+ *           false.
+ *         - {Boolean} remoteIframe
+ *           Flag to run the test with content wrapped in a remote iframe.
+ *           Default is false.
+ *         - {Object} iframeAttrs
+ *           A map of attribute/value pairs to be applied to IFRAME element.
+ *         - {Boolean} skipFissionDocLoad
+ *           If true, the test will not wait for iframe document document
+ *           loaded event (useful for when IFRAME is initially hidden).
+ *         - {Object} contentDocBodyAttrs
+ *           a set of attributes to be applied to a top level content document
+ *           body
+ *         - {Object} iframeDocBodyAttrs
+ *           a set of attributes to be applied to a iframe content document body
+ */
+function addAccessibleTask(doc, task, options = {}) {
+  const {
+    topLevel = true,
+    chrome = false,
+    iframe = false,
+    remoteIframe = false,
+  } = options;
+  if (topLevel) {
+    add_task(
+      accessibleTask(doc, task, {
+        ...options,
+        chrome: false,
+        iframe: false,
+        remoteIframe: false,
+      })
+    );
+  }
+
+  if (chrome) {
+    add_task(
+      accessibleTask(doc, task, {
+        ...options,
+        topLevel: false,
+        iframe: false,
+        remoteIframe: false,
+      })
+    );
+  }
+
+  if (iframe) {
+    add_task(
+      accessibleTask(doc, task, {
+        ...options,
+        topLevel: false,
+        chrome: false,
+        remoteIframe: false,
+      })
+    );
+  }
+
+  if (gFissionBrowser && remoteIframe) {
+    add_task(
+      accessibleTask(doc, task, {
+        ...options,
+        topLevel: false,
+        chrome: false,
+        iframe: false,
+      })
+    );
+  }
+}
+
+/**
+ * Check if an accessible object has a defunct test.
+ * @param  {nsIAccessible}  accessible object to test defunct state for
+ * @return {Boolean}        flag indicating defunct state
+ */
+function isDefunct(accessible) {
+  let defunct = false;
+  try {
+    let extState = {};
+    accessible.getState({}, extState);
+    defunct = extState.value & Ci.nsIAccessibleStates.EXT_STATE_DEFUNCT;
+  } catch (x) {
+    defunct = true;
+  } finally {
+    if (defunct) {
+      Logger.log(`Defunct accessible: ${prettyName(accessible)}`);
+    }
+  }
+  return defunct;
+}
+
+/**
+ * Get the DOM tag name for a given accessible.
+ * @param  {nsIAccessible}  accessible accessible
+ * @return {String?}                   tag name of associated DOM node, or null.
+ */
+function getAccessibleTagName(acc) {
+  try {
+    return acc.attributes.getStringProperty("tag");
+  } catch (e) {
+    return null;
+  }
+}
+
+/**
+ * Traverses the accessible tree starting from a given accessible as a root and
+ * looks for an accessible that matches based on its DOMNode id.
+ * @param  {nsIAccessible}  accessible root accessible
+ * @param  {String}         id         id to look up accessible for
+ * @param  {Array?}         interfaces the interface or an array interfaces
+ *                                     to query it/them from obtained accessible
+ * @return {nsIAccessible?}            found accessible if any
+ */
+function findAccessibleChildByID(accessible, id, interfaces) {
+  if (getAccessibleDOMNodeID(accessible) === id) {
+    return queryInterfaces(accessible, interfaces);
+  }
+  for (let i = 0; i < accessible.children.length; ++i) {
+    let found = findAccessibleChildByID(accessible.getChildAt(i), id);
+    if (found) {
+      return queryInterfaces(found, interfaces);
+    }
+  }
+  return null;
+}
+
+function queryInterfaces(accessible, interfaces) {
+  if (!interfaces) {
+    return accessible;
+  }
+
+  for (let iface of interfaces.filter(i => !(accessible instanceof i))) {
+    try {
+      accessible.QueryInterface(iface);
+    } catch (e) {
+      ok(false, "Can't query " + iface);
+    }
+  }
+
+  return accessible;
+}
+
+function arrayFromChildren(accessible) {
+  return Array.from({ length: accessible.childCount }, (c, i) =>
+    accessible.getChildAt(i)
+  );
+}
+
+/**
+ * Force garbage collection.
+ */
+function forceGC() {
+  SpecialPowers.gc();
+  SpecialPowers.forceShrinkingGC();
+  SpecialPowers.forceCC();
+  SpecialPowers.gc();
+  SpecialPowers.forceShrinkingGC();
+  SpecialPowers.forceCC();
+}
+
+/*
+ * This function spawns a content task and awaits expected mutation events from
+ * various content changes. It's good at catching events we did *not* expect. We
+ * do this advancing the layout refresh to flush the relocations/insertions
+ * queue.
+ */
+async function contentSpawnMutation(browser, waitFor, func, args = []) {
+  let onReorders = waitForEvents({ expected: waitFor.expected || [] });
+  let unexpectedListener = new UnexpectedEvents(waitFor.unexpected || []);
+
+  function tick() {
+    // 100ms is an arbitrary positive number to advance the clock.
+    // We don't need to advance the clock for a11y mutations, but other
+    // tick listeners may depend on an advancing clock with each refresh.
+    content.windowUtils.advanceTimeAndRefresh(100);
+  }
+
+  // This stops the refreh driver from doing its regular ticks, and leaves
+  // us in control.
+  await invokeContentTask(browser, [], tick);
+
+  // Perform the tree mutation.
+  await invokeContentTask(browser, args, func);
+
+  // Do one tick to flush our queue (insertions, relocations, etc.)
+  await invokeContentTask(browser, [], tick);
+
+  let events = await onReorders;
+
+  unexpectedListener.stop();
+
+  // Go back to normal refresh driver ticks.
+  await invokeContentTask(browser, [], function () {
+    content.windowUtils.restoreNormalRefresh();
+  });
+
+  return events;
+}
+
+async function waitForImageMap(browser, accDoc, id = "imgmap") {
+  let acc = findAccessibleChildByID(accDoc, id);
+
+  if (!acc) {
+    const onShow = waitForEvent(EVENT_SHOW, id);
+    acc = (await onShow).accessible;
+  }
+
+  if (acc.firstChild) {
+    return;
+  }
+
+  const onReorder = waitForEvent(EVENT_REORDER, id);
+  // Wave over image map
+  await invokeContentTask(browser, [id], contentId => {
+    const { ContentTaskUtils } = ChromeUtils.importESModule(
+      "resource://testing-common/ContentTaskUtils.sys.mjs"
+    );
+    const EventUtils = ContentTaskUtils.getEventUtils(content);
+    EventUtils.synthesizeMouse(
+      content.document.getElementById(contentId),
+      10,
+      10,
+      { type: "mousemove" },
+      content
+    );
+  });
+  await onReorder;
+}
+
+async function getContentBoundsForDOMElm(browser, id) {
+  return invokeContentTask(browser, [id], contentId => {
+    const { Layout: LayoutUtils } = ChromeUtils.importESModule(
+      "chrome://mochitests/content/browser/accessible/tests/browser/Layout.sys.mjs"
+    );
+
+    return LayoutUtils.getBoundsForDOMElm(contentId, content.document);
+  });
+}
+
+const CACHE_WAIT_TIMEOUT_MS = 5000;
+
+/**
+ * Wait for a predicate to be true after cache ticks.
+ * This function takes two callbacks, the condition is evaluated
+ * by calling the first callback with the arguments returned by the second.
+ * This allows us to asynchronously return the arguments as a result if the condition
+ * of the first callback is met, or if it times out. The returned arguments can then
+ * be used to record a pass or fail in the test.
+ */
+function untilCacheCondition(conditionFunc, argsFunc) {
+  return new Promise((resolve, reject) => {
+    let args = argsFunc();
+    if (conditionFunc(...args)) {
+      resolve(args);
+      return;
+    }
+
+    let cacheObserver = {
+      observe(subject) {
+        args = argsFunc();
+        if (conditionFunc(...args)) {
+          clearTimeout(this.timer);
+          Services.obs.removeObserver(this, "accessible-cache");
+          resolve(args);
+        }
+      },
+
+      timeout() {
+        ok(false, "Timeout while waiting for cache update");
+        Services.obs.removeObserver(this, "accessible-cache");
+        args = argsFunc();
+        resolve(args);
+      },
+    };
+
+    cacheObserver.timer = setTimeout(
+      cacheObserver.timeout.bind(cacheObserver),
+      CACHE_WAIT_TIMEOUT_MS
+    );
+    Services.obs.addObserver(cacheObserver, "accessible-cache");
+  });
+}
+
+function untilCacheOk(conditionFunc, message) {
+  return untilCacheCondition(
+    (v, _unusedMessage) => v,
+    () => [conditionFunc(), message]
+  ).then(([v, msg]) => ok(v, msg));
+}
+
+function untilCacheIs(retrievalFunc, expected, message) {
+  return untilCacheCondition(
+    (a, b, _unusedMessage) => Object.is(a, b),
+    () => [retrievalFunc(), expected, message]
+  ).then(([got, exp, msg]) => is(got, exp, msg));
+}
+
+async function waitForContentPaint(browser) {
+  await SpecialPowers.spawn(browser, [], () => {
+    return new Promise(function (r) {
+      content.requestAnimationFrame(() => content.setTimeout(r));
+    });
+  });
+}
+
+// Returns true if both number arrays match within `FUZZ`.
+function areBoundsFuzzyEqual(actual, expected) {
+  const FUZZ = 1;
+  return actual
+    .map((val, i) => Math.abs(val - expected[i]) <= FUZZ)
+    .reduce((a, b) => a && b, true);
+}
+
+function assertBoundsFuzzyEqual(actual, expected) {
+  ok(
+    areBoundsFuzzyEqual(actual, expected),
+    `${actual} fuzzily matches expected ${expected}`
+  );
+}
+
+async function testBoundsWithContent(iframeDocAcc, id, browser) {
+  // Retrieve layout bounds from content
+  let expectedBounds = await invokeContentTask(browser, [id], _id => {
+    const { Layout: LayoutUtils } = ChromeUtils.importESModule(
+      "chrome://mochitests/content/browser/accessible/tests/browser/Layout.sys.mjs"
+    );
+    return LayoutUtils.getBoundsForDOMElm(_id, content.document);
+  });
+
+  function isWithinExpected(bounds) {
+    return areBoundsFuzzyEqual(bounds, expectedBounds);
+  }
+
+  const acc = findAccessibleChildByID(iframeDocAcc, id);
+  let [accBounds] = await untilCacheCondition(isWithinExpected, () => [
+    getBounds(acc),
+  ]);
+
+  assertBoundsFuzzyEqual(accBounds, expectedBounds);
+
+  return accBounds;
+}