Remove the master-only directory.

The master-only directory has been unwieldy and in order to support LTS
an additional subset would be required which would make doing it by
directory even more unwieldy. The addition of a library for
conditionally defining LUCI resources depending on the branch means that
the builders for a bucket can be located together and the
branch_selector value controls which branches they are actually defined
for.

Bug: 1119446
Change-Id: I1dff1f8e6c0485e31fd902c383f02b37a3f0d138
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2378794Reviewed-by: Erik Staab <estaab@chromium.org>
Commit-Queue: Garrett Beaty <gbeaty@chromium.org>
Cr-Commit-Position: refs/heads/master@{#802046}

infra/config/dev.star

@@ -6,7 +6,7 @@
 # See https://chromium.googlesource.com/infra/luci/luci-go/+/HEAD/lucicfg/doc/README.md
 # for information on starlark/lucicfg
 
-load("//project.star", "master_only_exec")
+load("//lib/branches.star", "branches")
 
 lucicfg.check_version(
     min = "1.18.4",
@@ -29,4 +29,4 @@ lucicfg.config(
     fail_on_warnings = True,
 )
 
-master_only_exec("//dev/dev.star")
+branches.exec("//dev/dev.star")

infra/config/main.star

@@ -6,7 +6,8 @@
 # See https://chromium.googlesource.com/infra/luci/luci-go/+/HEAD/lucicfg/doc/README.md
 # for information on starlark/lucicfg
 
-load("//project.star", "master_only_exec", "settings")
+load("//lib/branches.star", "branches")
+load("//project.star", "settings")
 
 lucicfg.check_version(
     min = "1.18.4",
@@ -121,12 +122,12 @@ exec("//recipes.star")
 exec("//notifiers.star")
 
 exec("//subprojects/chromium/subproject.star")
-master_only_exec("//subprojects/codesearch/subproject.star")
-master_only_exec("//subprojects/findit/subproject.star")
-master_only_exec("//subprojects/goma/subproject.star")
-master_only_exec("//subprojects/webrtc/subproject.star")
+branches.exec("//subprojects/codesearch/subproject.star")
+branches.exec("//subprojects/findit/subproject.star")
+branches.exec("//subprojects/goma/subproject.star")
+branches.exec("//subprojects/webrtc/subproject.star")
 
-master_only_exec("//generators/cq-builders-md.star")
+branches.exec("//generators/cq-builders-md.star")
 
 # This should be exec'ed before exec'ing scheduler-noop-jobs.star because
 # attempting to read the buildbucket field that is not set for the noop jobs
@@ -135,7 +136,7 @@ master_only_exec("//generators/cq-builders-md.star")
 # problems when the number of builders with the same name goes from 1 to >1 or
 # vice-versa. This generator makes sure both the bucketed and non-bucketed IDs
 # work so that there aren't transient failures when the configuration changes
-master_only_exec("//generators/scheduler-bucketed-jobs.star")
+branches.exec("//generators/scheduler-bucketed-jobs.star")
 
 # TODO(https://crbug.com/819899) There are a number of noop jobs for dummy
 # builders defined due to legacy requirements that trybots mirror CI bots

infra/config/project.star

@@ -6,6 +6,8 @@ settings = struct(
     project = "chromium",
     # Switch this to False for branches
     is_master = True,
+    # Switch this to True for LTC/LTS branches
+    is_lts_branch = False,
     ref = "refs/heads/master",
     ci_bucket = "ci",
     ci_poller = "master-gitiles-trigger",
@@ -39,10 +41,6 @@ def _generate_project_pyl(ctx):
 
 lucicfg.generator(_generate_project_pyl)
 
-def master_only_exec(f):
-    if settings.is_master:
-        exec(f)
-
 # The branch numbers of branches that we have builders running for (including
 # milestone-specific projects)
 # Branch numbers for milestones can be viewed in the chromium column at

infra/config/subprojects/chromium/master-only/README.md

-Definitions of LUCI entities that only exist for the master branch.
-
-* **consoles**
-  * manually curated consoles for chromium subproject builders
-* **ci.star**
-  * builders that do post-submit testing against the master branch
-  * when new milestones are created, milestone-specific versions of the builders
-  will not be created
-* **try.star**, **gpu.try.star**, **swangle.try.star**
-  * builders that do pre-submit testing against the master branch
-  * when new milestones are created, milestone-specific versions of the builders
-  will not be created

infra/config/subprojects/chromium/master-only/master-only.star

-# Copyright 2020 The Chromium Authors. All rights reserved.
-# Use of this source code is governed by a BSD-style license that can be
-# found in the LICENSE file.
-
-# TODO(gbeaty) external_console_view uses new fields/types that aren't present
-# in the version of the protobuf that lint-luci-milo uses, so update protos and
-# then uncomment these (the main console is still reachable via the beta link in
-# the header)
-# luci.external_console_view(
-#     name = "main-m86",
-#     title = "Chromium M86 Main Console",
-#     source = "chromium-m86:main",
-# )
-
-# luci.external_console_view(
-#     name = "mirrors-m86",
-#     title = "Chromium M86 CQ Mirrors Console",
-#     source = "chromium-m86:mirrors",
-# )
-
-# luci.external_console_view(
-#     name = "try-m86",
-#     title = "Chromium M86 CQ Console",
-#     source = "chromium-m86:try",
-# )
-
-exec("./ci.star")
-exec("./gpu.try.star")
-exec("./swangle.try.star")
-exec("./try.star")
-
-exec("./consoles/android.packager.star")
-exec("./consoles/luci.chromium.try.star")
-exec("./consoles/metadata.exporter.star")
-exec("./consoles/sheriff.ios.star")
-
-exec("./fallback-cq.star")

infra/config/subprojects/chromium/subproject.star

@@ -2,9 +2,42 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
-load("//project.star", "master_only_exec")
+load("//lib/branches.star", "branches")
 
 exec("./ci.star")
 exec("./try.star")
+exec("./gpu.try.star")
+exec("./swangle.try.star")
 
-master_only_exec("./master-only/master-only.star")
+# Execute the M85 config
+branches.exec("./versioned/m85/buckets/ci.star")
+branches.exec("./versioned/m85/buckets/try.star")
+
+# TODO(gbeaty) external_console_view uses new fields/types that aren't present
+# in the version of the protobuf that lint-luci-milo uses, so update protos and
+# then uncomment these (the main console is still reachable via the beta link in
+# the header)
+# luci.external_console_view(
+#     name = "main-m86",
+#     title = "Chromium M86 Main Console",
+#     source = "chromium-m86:main",
+# )
+
+# luci.external_console_view(
+#     name = "mirrors-m86",
+#     title = "Chromium M86 CQ Mirrors Console",
+#     source = "chromium-m86:mirrors",
+# )
+
+# luci.external_console_view(
+#     name = "try-m86",
+#     title = "Chromium M86 CQ Console",
+#     source = "chromium-m86:try",
+# )
+
+branches.exec("./consoles/android.packager.star")
+branches.exec("./consoles/luci.chromium.try.star")
+branches.exec("./consoles/metadata.exporter.star")
+branches.exec("./consoles/sheriff.ios.star")
+
+branches.exec("./fallback-cq.star")