[FTR] Switch to new browser headless mode (#153828)

## Summary

This PR updates the way how we start the headless browser for testing.

The current way of starting in headless mode is eventually going away
and the new headless mode offers more capabilities and stability, see
https://www.selenium.dev/blog/2023/headless-is-going-away/ and
https://developer.chrome.com/articles/new-headless/.

### Test adjustments

All the adjusted discover, dashboard, maps and infra tests showed the
same pattern during failure investigation that's around the fact that
the new headless mode is closer to the regular / non-headless mode:
* Tests passed with the old headless mode
* Tests failed in regular / non-headless mode the same way they failed
in new headless mode
* The failure reasons were mostly around slightly different font
rendering and slightly different browser sizes

test/functional/apps/discover/group2/_data_grid_copy_to_clipboard.ts

@@ -64,7 +64,7 @@ export default function ({ getService, getPageObjects }: FtrProviderContext) {
 
       if (canReadClipboard) {
         const copiedSourceData = await browser.getClipboardValue();
-        expect(copiedSourceData.startsWith('"_source"\n{"@message":["238.171.34.42')).to.be(true);
+        expect(copiedSourceData.startsWith('Document\n{"@message":["238.171.34.42')).to.be(true);
         expect(copiedSourceData.endsWith('}')).to.be(true);
       }
 
@@ -89,7 +89,7 @@ export default function ({ getService, getPageObjects }: FtrProviderContext) {
 
       if (canReadClipboard) {
         const copiedSourceName = await browser.getClipboardValue();
-        expect(copiedSourceName).to.be('"_source"');
+        expect(copiedSourceName).to.be('Document');
       }
 
       expect(await toasts.getToastCount()).to.be(1);

test/functional/apps/discover/group2/index.ts

@@ -13,7 +13,7 @@ export default function ({ getService, loadTestFile }: FtrProviderContext) {
 
   describe('discover/group2', function () {
     before(async function () {
-      await browser.setWindowSize(1300, 800);
+      await browser.setWindowSize(1600, 1200);
     });
 
     after(async function unloadMakelogs() {

test/functional/services/remote/webdriver.ts

@@ -99,9 +99,12 @@ function initChromiumOptions(browserType: Browsers, acceptInsecureCerts: boolean
   }
 
   if (headlessBrowser === '1') {
+    // Using the new headless mode (instead of `options.headless()`)
+    // See: https://www.selenium.dev/blog/2023/headless-is-going-away/
+    options.addArguments('headless=new');
+
     // Use --disable-gpu to avoid an error from a missing Mesa library, as per
     // See: https://chromium.googlesource.com/chromium/src/+/lkgr/headless/README.md
-    options.headless();
     options.addArguments('disable-gpu');
   }
 
@@ -111,7 +114,11 @@ function initChromiumOptions(browserType: Browsers, acceptInsecureCerts: boolean
 
   if (remoteDebug === '1') {
     // Visit chrome://inspect in chrome to remotely view/debug
-    options.headless();
+
+    // Using the new headless mode (instead of `options.headless()`)
+    // See: https://www.selenium.dev/blog/2023/headless-is-going-away/
+    options.addArguments('headless=new');
+
     options.addArguments('disable-gpu', 'remote-debugging-port=9222');
   }
 

x-pack/test/functional/apps/infra/hosts_view.ts

@@ -160,6 +160,7 @@ export default ({ getPageObjects, getService }: FtrProviderContext) => {
         esArchiver.load('x-pack/test/functional/es_archives/infra/metrics_hosts_processes'),
         kibanaServer.savedObjects.cleanStandardList(),
       ]);
+      await browser.setWindowSize(1600, 1200);
     });
 
     after(() => {

x-pack/test/functional/apps/maps/group1/blended_vector_layer.js

@@ -35,7 +35,7 @@ export default function ({ getPageObjects, getService }) {
     it('should request clusters when zoomed to larger regions showing lots of data', async () => {
       await PageObjects.maps.setView(20, -90, 2);
       const { rawResponse: response } = await PageObjects.maps.getResponse();
-      expect(response.aggregations.gridSplit.buckets.length).to.equal(17);
+      expect(response.aggregations.gridSplit.buckets.length).to.equal(15);
     });
 
     it('should request documents when query narrows data', async () => {

x-pack/test/functional/apps/maps/group1/documents_source/search_hits.js

@@ -120,7 +120,7 @@ export default function ({ getPageObjects, getService }) {
         const { lat, lon, zoom } = await PageObjects.maps.getView();
         expect(Math.round(lat)).to.equal(43);
         expect(Math.round(lon)).to.equal(-102);
-        expect(Math.round(zoom)).to.equal(5);
+        expect(Math.round(zoom)).to.equal(4);
       });
     });
 

x-pack/test/functional/apps/maps/group2/es_geo_grid_source.js

@@ -53,7 +53,7 @@ export default function ({ getPageObjects, getService }) {
         });
 
         it('should not rerequest when pan changes do not move map view area outside of buffer', async () => {
-          await PageObjects.maps.setView(DATA_CENTER_LAT + 10, DATA_CENTER_LON + 10, 1);
+          await PageObjects.maps.setView(DATA_CENTER_LAT + 5, DATA_CENTER_LON + 5, 1);
           const afterTimestamp = await getRequestTimestamp();
           expect(afterTimestamp).to.equal(beforeTimestamp);
         });