Bug 1429236: put jsreftests in their own scheduling component; r=jmaher

This adds an 'override' for the default scheduling component for tests, which
is based on their suite.

MozReview-Commit-ID: 6vd8sb2zeuU

--HG--
extra : rebase_source : 25988c6790287e01fa7751effa72e8b924858948

taskcluster/ci/test/reftest.yml

@@ -52,6 +52,7 @@ crashtest:
 jsreftest:
     description: "JS Reftest run"
     suite: reftest/jsreftest
+    schedules-component: jsreftest  # scheduling for this reftest is different from the others..
     treeherder-symbol: R(J)
     instance-size:
         by-test-platform:

taskcluster/taskgraph/transforms/tests.py

@@ -34,6 +34,7 @@ from voluptuous import (
     Any,
     Optional,
     Required,
+    Exclusive,
 )
 
 import copy
@@ -379,10 +380,14 @@ test_description_schema = Schema({
     Optional('product'): basestring,
 
     # conditional files to determine when these tests should be run
-    Optional('when'): Any({
+    Exclusive(Optional('when'), 'optimization'): Any({
         Optional('files-changed'): [basestring],
     }),
 
+    # The SCHEDULES component for this task; this defaults to the suite
+    # (not including the flavor) but can be overridden here.
+    Exclusive(Optional('schedules-component'), 'optimization'): basestring,
+
     Optional('worker-type'): optionally_keyed_by(
         'test-platform',
         Any(basestring, None),
@@ -1008,7 +1013,7 @@ def make_job_description(config, tests):
             'platform': test.get('treeherder-machine-platform', test['build-platform']),
         }
 
-        suite = attributes['unittest_suite']
+        suite = test.get('schedules-component', attributes['unittest_suite'])
         if suite in INCLUSIVE_COMPONENTS:
             # if this is an "inclusive" test, then all files which might
             # cause it to run are annotated with SCHEDULES in moz.build,