Up the priority of tests on FYI bots that have optional CQ bot mirrors.

By default, all FYI tests run at pri 40, while all non-FYI tests run at pri 30.

Since some optional CQ bots mirror FYI bots, their tests run at a lower pri
than other CQ tests. Consequently, if the pool is in full use, there's a chance
that the optional tests will get starved out and expired. This leads to a blocked
CQ run if the CL in question is required to pass these optional bots via
"Cq-Include-Trybots" commit msg footer.

This increases priority of all known CQ-optional FYI bots to match normal CQ
tests.

Bug: 851115
Change-Id: I9c7625e498f098a6613729777d3782c2b4b6625c
Reviewed-on: https://chromium-review.googlesource.com/1097600Reviewed-by: John Budorick <jbudorick@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Commit-Queue: Ben Pastene <bpastene@chromium.org>
Cr-Commit-Position: refs/heads/master@{#566696}

testing/buildbot/chromium.fyi.json

@@ -1836,6 +1836,7 @@
         "name": "network_service_browser_tests",
         "swarming": {
           "can_use_on_swarming_builders": true,
+          "priority_adjustment": 30,
           "shards": 10
         },
         "test": "browser_tests"
@@ -1846,7 +1847,8 @@
         ],
         "name": "network_service_components_browsertests",
         "swarming": {
-          "can_use_on_swarming_builders": true
+          "can_use_on_swarming_builders": true,
+          "priority_adjustment": 30
         },
         "test": "components_browsertests"
       },
@@ -1857,7 +1859,8 @@
         ],
         "name": "network_service_content_browsertests",
         "swarming": {
-          "can_use_on_swarming_builders": true
+          "can_use_on_swarming_builders": true,
+          "priority_adjustment": 30
         },
         "test": "content_browsertests"
       },
@@ -1867,7 +1870,8 @@
         ],
         "name": "network_service_extensions_browsertests",
         "swarming": {
-          "can_use_on_swarming_builders": true
+          "can_use_on_swarming_builders": true,
+          "priority_adjustment": 30
         },
         "test": "extensions_browsertests"
       },
@@ -1878,6 +1882,7 @@
         "name": "network_service_interactive_ui_tests",
         "swarming": {
           "can_use_on_swarming_builders": true,
+          "priority_adjustment": 30,
           "shards": 2
         },
         "test": "interactive_ui_tests"
@@ -1900,6 +1905,7 @@
         "results_handler": "layout tests",
         "swarming": {
           "can_use_on_swarming_builders": true,
+          "priority_adjustment": 30,
           "shards": 12
         }
       }
@@ -4707,6 +4713,7 @@
             }
           ],
           "hard_timeout": 900,
+          "priority_adjustment": 30,
           "shards": 15
         }
       }

testing/buildbot/generate_buildbot_json.py

@@ -413,7 +413,8 @@ class BBJSONGenerator(object):
         'can_use_on_swarming_builders': tester_config.get('use_swarming', True)
       })
     if 'swarming' in tester_config:
-      if 'dimension_sets' not in generated_test['swarming']:
+      if ('dimension_sets' not in generated_test['swarming'] and
+          'dimension_sets' in tester_config['swarming']):
         generated_test['swarming']['dimension_sets'] = copy.deepcopy(
           tester_config['swarming']['dimension_sets'])
       self.dictionary_merge(generated_test['swarming'],

testing/buildbot/waterfalls.pyl

@@ -2309,6 +2309,13 @@
         },
       },
       'Mojo Linux': {
+        # Normally, FYI tests run with a lower priority than main CI tests.
+        # However, some optional CQ bots mirror FYI bots, so their tests need
+        # to run at the same priority as other non-optional CQ bots to avoid
+        # getting starved out.
+        'swarming': {
+          'priority_adjustment': 30,
+        },
         'test_suites': {
           'gtest_tests': 'network_service_gtests',
           'isolated_scripts': 'mojo_network_isolated_scripts',
@@ -2421,6 +2428,10 @@
         },
       },
       'WebKit Linux slimming_paint_v2 Dummy Builder': {
+        # Normally, FYI tests run with a lower priority than main CI tests.
+        # However, some optional CQ bots mirror FYI bots, so their tests need
+        # to run at the same priority as other non-optional CQ bots to avoid
+        # getting starved out.
         'swarming': {
           'dimension_sets': [
             {
@@ -2428,6 +2439,7 @@
             },
           ],
           'hard_timeout': 900,
+          'priority_adjustment': 30,
         },
         'test_suites': {
           'isolated_scripts': 'webkit_layout_tests_isolated_scripts',