Bug 1595985 - Add browser.urlbar.closeView webextension API. r=mak,mixedpuppy

This is based on D52612

Differential Revision: https://phabricator.services.mozilla.com/D52792

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

browser/components/extensions/parent/ext-urlbar.js

@@ -135,6 +135,11 @@ this.urlbar = class extends ExtensionAPI {
   getAPI(context) {
     return {
       urlbar: {
+        closeView() {
+          let window = windowTracker.getTopNormalWindow(context);
+          window.gURLBar.view.close();
+        },
+
         focus(select = false) {
           let window = windowTracker.getTopNormalWindow(context);
           if (select) {

browser/components/extensions/schemas/urlbar.json

@@ -114,6 +114,13 @@
       }
     },
     "functions": [
+      {
+        "name": "closeView",
+        "type": "function",
+        "async": true,
+        "description": "Closes the urlbar view in the current window.",
+        "parameters": []
+      },
       {
         "name": "focus",
         "type": "function",

browser/components/extensions/test/browser/browser_ext_urlbar.js

@@ -424,3 +424,24 @@ add_task(async function focusSelectTrue() {
 
   await ext.unload();
 });
+
+// Tests the closeView function.
+add_task(async function closeView() {
+  await UrlbarTestUtils.promiseAutocompleteResultPopup({
+    window,
+    waitForFocus,
+    value: "test",
+  });
+
+  let ext = ExtensionTestUtils.loadExtension({
+    manifest: {
+      permissions: ["urlbar"],
+    },
+    isPrivileged: true,
+    background: () => {
+      browser.urlbar.closeView();
+    },
+  });
+  await UrlbarTestUtils.promisePopupClose(window, () => ext.startup());
+  await ext.unload();
+});