Contributing to the Custom Tabs Examples

Want to contribute? Great! First, read this page.

Before you contribute

Before we can use your code, you must sign the Google Individual Contributor License Agreement (CLA), which you can do online, and it only takes a minute.

The CLA is necessary mainly because you own the copyright to your changes, even after your contribution becomes part of our codebase, so we need your permission to use and distribute your code. We also need to be sure of various other things—for instance that you‘ll tell us if you know that your code infringes on other people’s patents. You don‘t have to sign the CLA until after you’ve submitted your code for review and a member has approved it, but you must do it before we can put your code into our codebase. Before you start working on a larger contribution, you should get in touch with us first through the issue tracker with your idea so that we can help out and possibly guide you. Coordinating up front makes it much easier to avoid frustration later on.

If you are contributing on behalf of a corporation, you must fill out the Corporate Contributor License Agreement and send it to us as described on that page.

If you‘ve never submitted code before, you must add your (or your organization’s) name and contact info to the Chromium AUTHORS file.


All submissions, including submissions by project members, require review. We use Gerrit for this purpose.

Install depot_tools.

Then checkout the repo.

git clone

You can then create a local branch, make and commit your change.

cd custom-tabs-client
git checkout -b foo origin/master
... edit files ...
git commit -a

Once you're ready for a review do:

git cl upload

Once uploaded you can view the CL in Gerrit and request a review by clicking the ‘publish & mail’ link. The OWNERS file suggests relevant reviewers, but does not have any real power, any Chromium committer has the power to approve the change.

If you get review feedback, edit and commit locally and then do another upload with the new files. Before you commit you‘ll want to sync to the tip-of-tree. You can either merge or rebase, it’s up to you.

Then, submit your changes through the commit queue by checking the “Commit” box.

Once everything is landed, you can cleanup your branch.

git checkout master
git branch -D foo

Contributing from a Chromium checkout

If you already have this repo checked out as part of a Chromium checkout and want to edit it in place (instead of having a separate clone of the repository), you can use the exact same process as above.

When doing gclient sync in the Chromium tree, remember to switch back to the local branch master.

Updating Custom Tabs Examples in the Chromium tree (rolling DEPS)

To get your commit to be tested as part of the Chromium tree in src/third_party/custom_tabs_client, find the git hash of your landed commit in the repo.

Then edit Chrome's src/DEPS file. Look for a line like:

  Var('chromium_git') + '/custom-tabs-client.git' + '@' +

Update the value to the git hash you want to roll to, and contribute a codereview to Chromium for your edit. If you are a Chromium committer, feel free to TBR this.