Roll chromium to r488994

This patch rolls chromium past the r488926 which prevents chromium from
going to sleep on Mac OS X.

Fixes #100.

package.json

@@ -27,7 +27,7 @@
     "ws": "^3.0.0"
   },
   "puppeteer": {
-    "chromium_revision": "488823"
+    "chromium_revision": "488994"
   },
   "devDependencies": {
     "commonmark": "^0.27.0",

test/test.js

@@ -986,13 +986,6 @@ describe('Puppeteer', function() {
     }
   });
 
-  // FIXME: remove this when crbug.com/741689 is fixed.
-  it('RESTART BROWSER crbug.com/741689', SX(async function() {
-    page.close();
-    browser = new Browser({headless, args: ['--no-sandbox']});
-    page = await browser.newPage();
-  }));
-
   describe('Page.setUserAgent', function() {
     it('should work', SX(async function() {
       expect(page.userAgent()).toContain('Mozilla');