Allow a single trybot to mirror multiple waterfall bots.

scripts/slave/recipe_modules/chromium_tests/trybots.py

Index: scripts/slave/recipe_modules/chromium_tests/trybots.py
diff --git a/scripts/slave/recipe_modules/chromium_tests/trybots.py b/scripts/slave/recipe_modules/chromium_tests/trybots.py
index 94ba4593e404ddfda9979eb98bec1349384bffa5..435203d3ca231108cd4d51722e90229a26250da6 100644
--- a/scripts/slave/recipe_modules/chromium_tests/trybots.py
+++ b/scripts/slave/recipe_modules/chromium_tests/trybots.py
@@ -263,11 +263,18 @@ TRYBOTS = freeze({
         'mastername': 'chromium.chromiumos',
         'buildername': 'Linux ChromiumOS GN',
       },
-      'linux_chromium_rel_ng': {
-        'mastername': 'chromium.linux',
-        'buildername': 'Linux Builder',
-        'tester': 'Linux Tests',
-      },
+      'linux_chromium_rel_ng': [

[Paweł Hajdan Jr., 2016/01/11 18:41:11]

Whoa - can we experiment with an experimental builder, not main production
builder?

[Ken Russell (switch to Gerrit), 2016/01/11 22:54:01]

Sure, that'd be fine, though I think some test expectation suppressions in the
masters_recipe_test would still be needed. I don't know how to set up a new
tryserver from scratch and don't have the time to do so -- to be honest I think
this change to linux_chromium_rel_ng is not that intrusive and that it isn't
worth the extra day or so to bring up a new tryserver to experiment with.

The planned steps for this conversion were:

1. Get this CL working and landed.
2. Finish converting the chromium.gpu.fyi waterfall to the Chromium recipe.
(Working on this now)
3. Switch the chromium.gpu waterfall to the Chromium recipe. This should be easy
once (2) is done because all of the test targets will already have been tested
on all of the platforms.
4. Make a tiny change to both trybots.py and chromium_trybot.py to stop manually
adding the GPU tests to the bots with enable_gpu_tests set, and instead pick up
the tests from this file (and the associated src-side JSON files.)

I expect that (4) might need to be reverted and re-landed a couple of times, but
hopefully not.

Once (4) has stuck, the GPU recipe will be deleted.

I was hoping to have all of this done this week.

[Sergey Berezin, 2016/01/12 01:44:23]

+1 to Pawel's concern - let's not mess with a production builder. A single
mistake will make all 1K devs suffer.

What you can do easily instead is to create a new trybot which is a duplicate of
linux_chromium_rel_ng, but is not run by CQ. Add GPU builder/tester to it, and
add the builder to 10% CQ. This way, you'll have all the pieces tested
end-to-end, and have a steady stream of builds going without disrupting anybody
else's work.

You can add a new builder config to the master right away, and request the
master restart tonight. The builder will not be functional until this CL lands,
but it's OK, and will unblock your further testing. No new tryserver setup
needed.

[Ken Russell (switch to Gerrit), 2016/01/12 05:35:51]

OK. Agree it's much better to get the entire system running end-to-end. The new
trybot would have the advantage that it wouldn't be listed in the
CHROMIUM_GPU_DIMENSION_SETS in chromium_trybot.py.

I would really appreciate help getting all of this set up. Since Pawel
volunteered to carry forward this CL I'd appreciate it if the experimental setup
could also be handled by him and the rest of the CQ team.

+        {
+          'mastername': 'chromium.linux',
+          'buildername': 'Linux Builder',
+          'tester': 'Linux Tests',
+        },
+        {
+          'mastername': 'chromium.gpu',
+          'buildername': 'GPU Fake Linux Builder',
+          'tester': 'Fake Linux Release (NVIDIA)',
+        },
+      ],
       'linux_chromium_asan_rel_ng': {
         'mastername': 'chromium.memory',
         'buildername': 'Linux ASan LSan Builder',