1# Updating Chromium's about:tracing (rolling DEPS)
2
3Chromium's DEPS file needs to be rolled to the catapult revision containing your
4change in order for it to appear in Chrome's about:tracing or other
5third_party/catapult files. This should happen automatically, but you may need
6to do it manually in rare cases. See below for more details.
7
8## Automatic rolls
9
10DEPS should be automatically rolled by the auto-roll bot at
11[catapult-roll.skia.org](https://catapult-roll.skia.org/).
12[catapult-sheriff@chromium.org](https://groups.google.com/a/chromium.org/forum/#!forum/catapult-sheriff)
13will be cc-ed on all reviews, and anyone who wants to join that list can
14subscribe. It's also the correct list to report a problem with the autoroll. If
15you need to stop the autoroll, either sign into that page with a google.com
16account, or contact catapult-sheriff@chromium.org.
17
18## Manual rolls
19
20In rare cases, you may need to make changes to chromium at the same time as you
21roll catapult DEPs. In this case you would need to do a manual roll. Here are
22instructions for rolling catapult DEPS, your CL would also include any other
23changes to chromium needed to complete the roll.
24
25First, commit to catapult. Then check the [mirror]
26(https://chromium.googlesource.com/external/github.com/catapult-project/catapult.git)
27to find the git hash of your commit. (Note: it may take a few minutes to be
28mirrored).
29
30Then edit Chrome's [src/DEPS]
31(https://code.google.com/p/chromium/codesearch#chromium/src/DEPS) file. Look for
32a line like:
33
34```
35  'src/third_party/catapult':
36    Var('chromium_git') + '/external/github.com/catapult-project/catapult.git' + '@' +
37    '2da8924915bd6fb7609c518f5b1f63cb606248eb',
38```
39
40Update the number to the git hash you want to roll to, and [contribute a
41codereview to chrome](http://www.chromium.org/developers/contributing-code)
42for your edit. If you are a Chromium committer, feel free to TBR this.
43