Here is what's desired: ability to use Gerrit by a developer even though default is Rietveld in codereview.settings. Currently, there is a way to opt-in completely with "git config gerrit.host true", but it applies to ALL branches overriding rietveld default.

I have currently code which adds '--gerrit' and'--rietveld' as option "git cl upload" and "git cl patch" and "git cl issue XXX". It's then possible to have the same CL branch uploaded gerrit and rietveld, while being in the same branch (i won't support it though).

This is almost ready - still blocked on CLs pending in other bugs on which this one is blocked.

There is another related but independent bug for CQ auto_deploy to launch two CQs for such projects though.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/tools/depot_tools.git/+/4c72b08fce5faf1b3ad83077dd39712b6248ee03

commit 4c72b08fce5faf1b3ad83077dd39712b6248ee03
Author: tandrii@chromium.org <tandrii@chromium.org>
Date: Thu Mar 31 22:26:35 2016

Gerrit git cl: do per CL check for Gerrit, not repo-wide.

The purpose is to allow mixed usage of Rietveld/Gerrit in the same repo.
There, a branch can use Gerrit, even though repo's default is Rietveld.
The only remaining repo-wide check GetIsGerrit is to determine codereview
for a branch which has no uploads yet.

This also simplifies future test expectations.

R=andybons@chromium.org,bauerb@chromium.org
BUG= 598681 

Review URL: https://codereview.chromium.org/1851663002

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@299603 0039d316-1c4b-4281-b951-d872f2087c98

[modify] https://crrev.com/4c72b08fce5faf1b3ad83077dd39712b6248ee03/git_cl.py
[modify] https://crrev.com/4c72b08fce5faf1b3ad83077dd39712b6248ee03/tests/git_cl_test.py

Also landed this https://codereview.chromium.org/1873233002/
which supports "git cl checkout <issue either gerrit or rietveld>" in mixed repos.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/tools/depot_tools.git/+/dde6462520224897393e13d1a9f421166beac08e

commit dde6462520224897393e13d1a9f421166beac08e
Author: tandrii@chromium.org <tandrii@chromium.org>
Date: Wed Apr 13 17:11:21 2016

git cl: add --gerrit and --rietveld options to force codereview.

This makes it possible to override the codereview set in:
 * repository codereview.settings
 * cached/set in local .git/config, either repo-wide or
   current branch only.

Examples:

    cd $SOME_RIETVELD_USING_REPO
    # Enable Gerrit codereview on it. Contact Infra-Git admin:
    # https://bugs.chromium.org/p/chromium/issues/entry?template=Infra-Git

    # Uploading
    git cl upload --gerrit --squash
    # Hack, hack, re-upload uses Gerrit automatically.
    git cl upload --squash

    # Patching
    git new-branch patched-in-issue
    git cl patch --gerrit XXXXXX

    # (Re-)setting issue
    git cl issue --gerrit 0
    git cl issue --gerrit XXXXXX

R=andybons@chromium.org,sergiyb@chromium.org
BUG= 598681 

Review URL: https://codereview.chromium.org/1880243003

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/depot_tools@299901 0039d316-1c4b-4281-b951-d872f2087c98

[modify] https://crrev.com/dde6462520224897393e13d1a9f421166beac08e/git_cl.py
[modify] https://crrev.com/dde6462520224897393e13d1a9f421166beac08e/tests/git_cl_test.py

I think this is fixed.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/tools/build.git/+/876d15a946ad1c7a46e85c71cbc8acc41b75f23d

commit 876d15a946ad1c7a46e85c71cbc8acc41b75f23d
Author: recipe-roller@chromium.org <recipe-roller@chromium.org>
Date: Wed Apr 13 17:18:28 2016

Roll recipe dependencies (trivial).

This is an automated CL created by the recipe roller. This CL rolls recipe
changes from upstream projects (e.g. depot_tools) into downstream projects
(e.g. tools/build).


More info is at https://goo.gl/zkKdpD. Use https://goo.gl/noib3a to file a bug
(or complain)

depot_tools:
  https://crrev.com/fa330e80123fb9634c954ef5ab844f86a3ef9b22 git cl set-commit: for Gerrit + dry-run support. (tandrii@chromium.org)
  https://crrev.com/dde6462520224897393e13d1a9f421166beac08e git cl: add --gerrit and --rietveld options to force codereview. (tandrii@chromium.org)

R=andybons@chromium.org,phajdan.jr@chromium.org,sergiyb@chromium.org,tandrii@chromium.org
BUG= 599931 , 598681 

TBR=martiniss@chromium.org,phajdan.jr@chromium.org

Review URL: https://codereview.chromium.org/1888523002

git-svn-id: svn://svn.chromium.org/chrome/trunk/tools/build@299902 0039d316-1c4b-4281-b951-d872f2087c98

[modify] https://crrev.com/876d15a946ad1c7a46e85c71cbc8acc41b75f23d/infra/config/recipes.cfg