feat(chromium): roll Chromium to r568432 (#2769)

This roll includes:
- https://crrev.com/568341 - DevTools: force-create execution contexts for mixed content iframes

Fixes #2709.

package.json

@@ -8,7 +8,7 @@
     "node": ">=6.4.0"
   },
   "puppeteer": {
-    "chromium_revision": "567388"
+    "chromium_revision": "568432"
   },
   "scripts": {
     "unit": "node test/test.js",

test/ignorehttpserrors.spec.js

@@ -58,6 +58,11 @@ module.exports.addTests = function({testRunner, expect, PROJECT_ROOT, defaultBro
         res.end(`<iframe src=${server.EMPTY_PAGE}></iframe>`);
       });
       await page.goto(httpsServer.PREFIX + '/mixedcontent.html', {waitUntil: 'load'});
+      expect(page.frames().length).toBe(2);
+      // Make sure blocked iframe has functional execution context
+      // @see https://github.com/GoogleChrome/puppeteer/issues/2709
+      expect(await page.frames()[0].evaluate('1 + 2')).toBe(3);
+      expect(await page.frames()[1].evaluate('2 + 3')).toBe(5);
     });
   });
 };