Update rietveld references in catapult docs to Gerrit.

CONTRIBUTING.md

Index: CONTRIBUTING.md
diff --git a/CONTRIBUTING.md b/CONTRIBUTING.md
index f303a173c23ef24044cfab8922c52fa851227ce5..3f0ed068bc81e8a2b8e5def0293cd403f3c5e5a1 100644
--- a/CONTRIBUTING.md
+++ b/CONTRIBUTING.md
@@ -28,11 +28,11 @@ git commit -a -m "New files"
 
 Once you're ready for a review do:
 
-`git cl upload --rietveld`
+`git cl upload`
 
-Once uploaded you can view the CL in Rietveld and **request a review** by
-clicking the 'publish & mail' link, and adding a reviewer from the
-[OWNERS](/OWNERS) file. You can also click the "CQ Dry Run" link to run all
+Once uploaded you can view the CL in Gerrit and **request a review** by
+clicking the "Add reviewer" link, and adding a reviewer from the
+[OWNERS](/OWNERS) file. You can also click the "CQ Dry Run" button to run all
 the tests on your change.
 
 If you get review feedback, edit and commit locally and then do another upload
@@ -104,9 +104,9 @@ Look to individual project documentation for more info on getting started:
 Check individual project documentation for instructions on how to run tests.
 You can also check the current status of our tests on the
 [waterfall](http://build.chromium.org/p/client.catapult/waterfall).
-Use the "commit" checkbox in rietveld to commit through the commit queue, which
-automatically runs all tests. Run the tests before committing with the
-"CQ dry run" link.
+Use the "Submit to CQ" button in Gerrit to commit through the commit queue,
+which automatically runs all tests. Run the tests before committing with the
+"CQ Dry Run" button.
 
 # Updating Chromium's about:tracing (rolling DEPS)