Bug 1602611 - fix browser_menuButtonFitts.js to wait for resizes on Linux, r=jaws

Differential Revision: https://phabricator.services.mozilla.com/D61502

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

browser/base/content/test/general/browser.ini

@@ -266,7 +266,6 @@ skip-if = e10s # Bug 863514 - no gesture support.
 skip-if = toolkit == "windows" # Disabled on Windows due to frequent failures (bug 969405)
 # DO NOT ADD MORE TESTS HERE. USE A TOPICAL DIRECTORY INSTEAD.
 [browser_menuButtonFitts.js]
-skip-if = os == 'linux' && os_version == '18.04' # Bug 1602611
 # DO NOT ADD MORE TESTS HERE. USE A TOPICAL DIRECTORY INSTEAD.
 [browser_middleMouse_noJSPaste.js]
 # DO NOT ADD MORE TESTS HERE. USE A TOPICAL DIRECTORY INSTEAD.

browser/base/content/test/general/browser_menuButtonFitts.js

@@ -2,9 +2,22 @@
  * http://creativecommons.org/publicdomain/zero/1.0/
  */
 
-function test() {
-  waitForExplicitFinish();
+"use strict";
+
+/**
+ * Clicking the right end of a maximized window should open the hamburger menu.
+ */
+add_task(async function test_clicking_hamburger_edge_fitts() {
+  let oldWidth = window.outerWidth;
+  let maximizeDone = BrowserTestUtils.waitForEvent(
+    window,
+    "resize",
+    false,
+    () => window.outerWidth >= screen.width - 1
+  );
   window.maximize();
+  // Ensure we actually finish the resize before continuing.
+  await maximizeDone;
 
   // Find where the nav-bar is vertically.
   var navBar = document.getElementById("nav-bar");
@@ -12,10 +25,24 @@ function test() {
   var yPixel = boundingRect.top + Math.floor(boundingRect.height / 2);
   var xPixel = boundingRect.width - 1; // Use the last pixel of the screen since it is maximized.
 
-  function onPopupHidden() {
+  let popupHiddenResolve;
+  let popupHiddenPromise = new Promise(resolve => {
+    popupHiddenResolve = resolve;
+  });
+  async function onPopupHidden() {
     PanelUI.panel.removeEventListener("popuphidden", onPopupHidden);
+    let restoreDone = BrowserTestUtils.waitForEvent(
+      window,
+      "resize",
+      false,
+      () => {
+        let w = window.outerWidth;
+        return w > oldWidth - 5 && w < oldWidth + 5;
+      }
+    );
     window.restore();
-    finish();
+    await restoreDone;
+    popupHiddenResolve();
   }
   function onPopupShown() {
     PanelUI.panel.removeEventListener("popupshown", onPopupShown);
@@ -29,4 +56,5 @@ function test() {
   });
   PanelUI.panel.addEventListener("popupshown", onPopupShown);
   EventUtils.synthesizeMouseAtPoint(xPixel, yPixel, {}, window);
-}
+  await popupHiddenPromise;
+});