Want to contribute? Great! First, read this page (including the small print at the end).

Before you contribute

Before we can use your code, you must sign the Google Individual Contributor License Agreement (CLA), which you can do online. 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. Co-ordinating large changes ahead of time can avoid frustration later on.

Code reviews

All submissions - including submissions by project members - require review. We use GitHub pull requests for this purpose. GitHub will automatically run the tests when you mail your pull request and a proper review won’t be started until the tests are complete and passing.

Code Style

All code submissions should try to match the surrounding code. Wherever possible, code should adhere to either the Google Objective-C Style Guide or the Google C++ Style Guide.

Identifier Conventions

All submissions related to the use of different identifiers should adhere to the following conventions.

Identifier	Notes	Example
SHA-256	lowercase	801d1dd8bc78984c126a269aca053642d16eef4389dfdc8df575af929fdcf279
CDHash	lowercase	2d1cff4b1080058e7e5913e5a3398bcd0199b6a4
TeamID	uppercase	43AQ936H96
Signing ID	case insensitive	EQHXZ8M8AV:com.google.Chrome

The small print

Contributions made by corporations are covered by a different agreement than the one above, the Software Grant and Corporate Contributor License Agreement.