Fixup the contributing file.

The CONTRIBUTING was written before the decision to use the
dawn-reviews. This CL updates to the correct information.

Bug: tint:36
Change-Id: I7e15572a3ed4bc4bbaaba8972e84eeda111d953f
Reviewed-on: https://dawn-review.googlesource.com/c/tint/+/18921
Reviewed-by: Ryan Harrison <rharrison@chromium.org>
Commit-Queue: Ryan Harrison <rharrison@chromium.org>
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index db177d4..43bb483 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -18,9 +18,12 @@
 ## Code reviews
 
 All submissions, including submissions by project members, require review. We
-use GitHub pull requests for this purpose. Consult
-[GitHub Help](https://help.github.com/articles/about-pull-requests/) for more
-information on using pull requests.
+use [Dawn's Gerrit](https://dawn-review.googlesource.com/) for this purpose.
+
+Tint generally follows the Google C++ style guide. There is a clang-format file
+provided and a `tools/format` script which will run the formatter. There is also
+a `tools/lint` script to run a linter. Overall try to use the same style and
+convention as code around your change.
 
 ## Community Guidelines