Update early hints document

Now it's enabled by default. Remove text related to activation. Bug: N/A Change-Id: I65d1abb13f7e635bb287991cb7f2a925737c288e Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/4258666 Commit-Queue: Kenichi Ishibashi <bashi@chromium.org> Reviewed-by: Adam Rice <ricea@chromium.org> Cr-Commit-Position: refs/heads/main@{#1106042}
chromium · Feb 16, 2023 · 392a760 · 392a760
1 parent 4f801d0
commit 392a760
Showing 1 changed file with 6 additions and 49 deletions.
diff --git a/docs/early-hints.md b/docs/early-hints.md
@@ -1,19 +1,14 @@
 # 103 Early Hints
 
-Contact: early-hints-experiment@chromium.org
+Contact: net-dev@chromium.org
 
-As of version 95, Chrome experimentally supports
+As of version 103, Chrome supports
 [Early Hints](https://datatracker.ietf.org/doc/html/rfc8297).
 Early Hints enable browsers to preload subresources or preconnect to servers
 before the main response is served. See the
 [explainer](https://github.com/bashi/early-hints-explainer/blob/main/explainer.md)
 how it works.
 
-Currently Chrome is running A/B testing in the field to evaluate the performance
-impact of Early Hints. Chrome also provides some ways to opt-in Early Hints for
-web developers who want to try the feature. This document describes the status
-of the current implementation and how to enable Early Hints support.
-
 ## What’s supported
 
 Chrome supports [preload](https://w3c.github.io/preload/) and
@@ -39,48 +34,7 @@ Chrome doesn’t handle
 [prefetch](https://w3c.github.io/resource-hints/#dfn-prefetch) in Early Hints
 yet. We consider supporting them in the future.
 
-## Activation
-
-Early Hints can be enabled by a command line flag, or via
-[Origin Trial](https://developer.chrome.com/blog/origin-trials/).
-
-### Using command line flag
-
-Passing the `--enable-features=EarlyHintsPreloadForNavigation` command line flag
-to Chrome enables Early Hints support.
-
-### Using Origin Trial
-
-**Note**: As of version 98 the origin trial has expired. The Chrome networking
-team is preparing to ship the feature and the origin trial may be available
-again in the near future until it's fully shipped.
-
-You can opt any page on your origin into Early Hints by
-[requesting a token for your origin](https://developer.chrome.com/origintrials/#/view_trial/2856408063659737089).
-Include the token in both Early Hints and the final response so that Chrome can
-recognize your pages opted in Early Hints.
-
-```
-HTTP/1.1 103 Early Hints
-Origin-Trial: **your token**
-Link: </style.css>; rel="preload"; as="style"
-Link: <https://cdn.test>; rel="preconnect"
-
-HTTP/1.1 200 OK
-Origin-Trial: **your token**
-Link: </style.css>; rel="preload"; as="style"
-Link: <https://cdn.test>; rel="preconnect"
-Content-Type: text/html; charset=utf-8
-
-<!DOCTYPE html>
-...
-```
-
-`<meta http-equiv="origin-trial" content="**your token**">` also works for the
-final response but doesn’t work for Early Hints since Early Hints cannot convey
-a response body.
-
-### Checking Early Hints preload is working
+## Checking Early Hints preload is working
 
 If a resource is preloaded by Early Hints, the corresponding
 [PerformanceResourceTiming](https://w3c.github.io/resource-timing/#sec-performanceresourcetiming)
@@ -90,6 +44,9 @@ performance.getEntriesByName('https://a.test/style.css')[0].initiatorType
 // => 'early-hints'
 ```
 
+Caveat: `initiatorType` may not always set to "early-hints" due to an
+implementation limitation. We would like to fix the issue in the future.
+
 ## Resources
 
 * [Fastly's test page](https://early-hints.fastlylabs.com/)