
Create a client-configured field trial, SeedFileTrial, with two possible groups, a treatment group that will use the seed files group and a control group which will continue with status quo behavior. This CL also does the following: * Involved considering multiple different options for where to have the field trial setup take place with the following options considered: - In the SeedReaderWriter, rejected because, since both the safe seed store and the latest seed store have a corresponding SeedReaderWriter, we would be doing the setup twice. - In the VariationService, rejected because, by wanting to consolidate logic, it did not feel as correct of a spot as the seed store. * Removes plumbing channel to the SeedReaderWriter as well as the logic related to the channel in SeedReaderWriter. This is because behavior will now be determined by the field trial group instead of the release channel of a client. * Renames kDefaultGroup to kTestDefaultGroup in unittest to avoid naming collision Bug: 371181951 Change-Id: Ia870df79d4e00bd0fe272441a196e0ee75064c0e Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5907254 Reviewed-by: Caitlin Fischer <caitlinfischer@google.com> Reviewed-by: Nate Fischer <ntfschr@chromium.org> Commit-Queue: Cristian Lopez <cristiandlopez@google.com> Cr-Commit-Position: refs/heads/main@{#1379240}
Headless Chromium
Headless Chromium allows running Chromium in a headless/server environment. Expected use cases include loading web pages, extracting metadata (e.g., the DOM) and generating bitmaps from page contents -- using all the modern web platform features provided by Chromium and Blink.
As of M118, precompiled headless_shell
binaries are available for download
under the name chrome-headless-shell
via Chrome for Testing
infrastructure.
There are two ways to use Headless Chromium:
Usage via the DevTools remote debugging protocol
- Start a normal Chrome binary with the
--headless=old
command line flag:
$ chrome --headless=old --remote-debugging-port=9222 https://chromium.org/
- Navigate to
chrome://inspect/
in another instance of Chrome.
Usage from Node.js
For example, the chrome-remote-interface Node.js package can be used to extract a page's DOM like this:
const CDP = require('chrome-remote-interface');
(async () => {
let client;
try {
// Connect to browser
client = await CDP();
// Extract used DevTools domains.
const {Page, Runtime} = client;
// Enable events on domains we are interested in.
await Page.enable();
await Page.navigate({url: 'https://example.com'});
await Page.loadEventFired();
// Evaluate outerHTML after page has loaded.
const expression = {expression: 'document.body.outerHTML'};
const { result } = await Runtime.evaluate(expression);
console.log(result.value);
} catch (err) {
console.error('Cannot connect to browser:', err);
} finally {
if (client) {
await client.close();
}
}
})();
Alternatvely, the Puppeteer Node.js package can be used to communicate with headless, for example:
import puppeteer from 'puppeteer';
(async () => {
const browser = await puppeteer.launch({headless: 'shell'});
const page = await browser.newPage();
await page.goto('https://example.com');
const title = await page.evaluate(() => document.title);
console.log(title);
await browser.close();
})();
Resources and Documentation
Mailing list: headless-dev@chromium.org
Bug tracker: Internals>Headless
File a new bug (bit.ly/2pP6SBb)
- Runtime headless mode on Windows OS
- BeginFrame sequence numbers + acknowledgements
- Deterministic page loading for Blink
- Crash dumps for Headless Chrome
- Runtime headless mode for Chrome
- Virtual Time in Blink
- Headless Chrome architecture (Design Doc)
- Session isolation in Headless Chrome
- Headless Chrome mojo service
- Controlling BeginFrame through DevTools
- Viewport bounds and scale for screenshots
- BlinkOn 6 presentation slides