Import upstream commit that fixes pageAction-related test

This imports commit 9e1691779afd5943e4a12ff95e69722b41f5c185 from mozilla-central
Bug 1221539 - Add search engine discovery to the page action menu. Part 1: Page action changes.

test/addon/browser_screenshots_ui_check.js

@@ -8,17 +8,84 @@ function checkElements(expectPresent, l) {
   }
 }
 
+async function togglePageActionPanel() {
+  await promiseOpenPageActionPanel();
+  EventUtils.synthesizeMouseAtCenter(BrowserPageActions.mainButtonNode, {});
+  await promisePageActionPanelEvent("popuphidden");
+}
+
+function promiseOpenPageActionPanel() {
+  let dwu = window.QueryInterface(Ci.nsIInterfaceRequestor)
+                  .getInterface(Ci.nsIDOMWindowUtils);
+  return BrowserTestUtils.waitForCondition(() => {
+    // Wait for the main page action button to become visible.  It's hidden for
+    // some URIs, so depending on when this is called, it may not yet be quite
+    // visible.  It's up to the caller to make sure it will be visible.
+    info("Waiting for main page action button to have non-0 size");
+    let bounds = dwu.getBoundsWithoutFlushing(BrowserPageActions.mainButtonNode);
+    return bounds.width > 0 && bounds.height > 0;
+  }).then(() => {
+    // Wait for the panel to become open, by clicking the button if necessary.
+    info("Waiting for main page action panel to be open");
+    if (BrowserPageActions.panelNode.state == "open") {
+      return Promise.resolve();
+    }
+    let shownPromise = promisePageActionPanelEvent("popupshown");
+    EventUtils.synthesizeMouseAtCenter(BrowserPageActions.mainButtonNode, {});
+    return shownPromise;
+  }).then(() => {
+    // Wait for items in the panel to become visible.
+    return promisePageActionViewChildrenVisible(BrowserPageActions.mainViewNode);
+  });
+}
+
+function promisePageActionPanelEvent(eventType) {
+  return new Promise(resolve => {
+    let panel = BrowserPageActions.panelNode;
+    if ((eventType == "popupshown" && panel.state == "open") ||
+        (eventType == "popuphidden" && panel.state == "closed")) {
+      executeSoon(resolve);
+      return;
+    }
+    panel.addEventListener(eventType, () => {
+      executeSoon(resolve);
+    }, { once: true });
+  });
+}
+
+function promisePageActionViewChildrenVisible(panelViewNode) {
+  info("promisePageActionViewChildrenVisible waiting for a child node to be visible");
+  let dwu = window.QueryInterface(Ci.nsIInterfaceRequestor)
+                  .getInterface(Ci.nsIDOMWindowUtils);
+  return BrowserTestUtils.waitForCondition(() => {
+    let bodyNode = panelViewNode.firstChild;
+    for (let childNode of bodyNode.childNodes) {
+      let bounds = dwu.getBoundsWithoutFlushing(childNode);
+      if (bounds.width > 0 && bounds.height > 0) {
+        return true;
+      }
+    }
+    return false;
+  });
+}
+
 add_task(async function() {
   await promiseScreenshotsEnabled();
 
   registerCleanupFunction(async function() {
     await promiseScreenshotsReset();
   });
 
+  // Toggle the page action panel to get it to rebuild itself.  An actionable
+  // page must be opened first.
+  let url = "http://example.com/browser_screenshots_ui_check";
+  await BrowserTestUtils.withNewTab(url, async () => {
+    await togglePageActionPanel();
 
-  await BrowserTestUtils.waitForCondition(
-    () => document.getElementById(BUTTON_ID),
-    "Screenshots button should be present", 100, 100);
+    await BrowserTestUtils.waitForCondition(
+      () => document.getElementById(BUTTON_ID),
+      "Screenshots button should be present", 100, 100);
 
-  checkElements(true, [BUTTON_ID]);
+    checkElements(true, [BUTTON_ID]);
+  });
 });