[mac-rel-swarming] add arm-64 Mac to the target bots

ARM Mac bots have 'arm64' cpu dimension.
https://chromium-swarm-dev.appspot.com/bot?id=build201-a9

Adding Ignore-CQ-Freeze because this isn't for production.

Ignore-CQ-Freeze: true
Bug: 1103470
Change-Id: I3d3713909994a88224aec6c9eaf48e9d0890d2ab
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2320714
Commit-Queue: Junji Watanabe <jwata@google.com>
Reviewed-by: Ben Pastene <bpastene@chromium.org>
Reviewed-by: Erik Staab <estaab@chromium.org>
Reviewed-by: Takuto Ikuta <tikuta@chromium.org>
Auto-Submit: Junji Watanabe <jwata@google.com>
Cr-Commit-Position: refs/heads/master@{#792461}

testing/buildbot/chrome.ci.json

@@ -3799,6 +3799,11 @@
         },
         "swarming": {
           "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64|arm64"
+            }
+          ],
           "service_account": "chromium-tester-dev@chops-service-accounts.iam.gserviceaccount.com"
         },
         "test": "base_unittests",
@@ -3811,6 +3816,11 @@
         },
         "swarming": {
           "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64|arm64"
+            }
+          ],
           "service_account": "chromium-tester-dev@chops-service-accounts.iam.gserviceaccount.com"
         },
         "test": "content_browsertests",
@@ -3823,6 +3833,11 @@
         },
         "swarming": {
           "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64|arm64"
+            }
+          ],
           "service_account": "chromium-tester-dev@chops-service-accounts.iam.gserviceaccount.com"
         },
         "test": "content_unittests",
@@ -3835,6 +3850,11 @@
         },
         "swarming": {
           "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64|arm64"
+            }
+          ],
           "service_account": "chromium-tester-dev@chops-service-accounts.iam.gserviceaccount.com"
         },
         "test": "interactive_ui_tests",
@@ -3847,6 +3867,11 @@
         },
         "swarming": {
           "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64|arm64"
+            }
+          ],
           "service_account": "chromium-tester-dev@chops-service-accounts.iam.gserviceaccount.com"
         },
         "test": "net_unittests",
@@ -3859,6 +3884,11 @@
         },
         "swarming": {
           "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64|arm64"
+            }
+          ],
           "service_account": "chromium-tester-dev@chops-service-accounts.iam.gserviceaccount.com"
         },
         "test": "unit_tests",

testing/buildbot/chromium.dev.json

@@ -902,6 +902,11 @@
         },
         "swarming": {
           "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64|arm64"
+            }
+          ],
           "service_account": "chromium-tester-dev@chops-service-accounts.iam.gserviceaccount.com"
         },
         "test": "base_unittests",
@@ -914,6 +919,11 @@
         },
         "swarming": {
           "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64|arm64"
+            }
+          ],
           "service_account": "chromium-tester-dev@chops-service-accounts.iam.gserviceaccount.com"
         },
         "test": "content_browsertests",
@@ -926,6 +936,11 @@
         },
         "swarming": {
           "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64|arm64"
+            }
+          ],
           "service_account": "chromium-tester-dev@chops-service-accounts.iam.gserviceaccount.com"
         },
         "test": "content_unittests",
@@ -938,6 +953,11 @@
         },
         "swarming": {
           "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64|arm64"
+            }
+          ],
           "service_account": "chromium-tester-dev@chops-service-accounts.iam.gserviceaccount.com"
         },
         "test": "interactive_ui_tests",
@@ -950,6 +970,11 @@
         },
         "swarming": {
           "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64|arm64"
+            }
+          ],
           "service_account": "chromium-tester-dev@chops-service-accounts.iam.gserviceaccount.com"
         },
         "test": "net_unittests",
@@ -962,6 +987,11 @@
         },
         "swarming": {
           "can_use_on_swarming_builders": true,
+          "dimension_sets": [
+            {
+              "cpu": "x86-64|arm64"
+            }
+          ],
           "service_account": "chromium-tester-dev@chops-service-accounts.iam.gserviceaccount.com"
         },
         "test": "unit_tests",

testing/buildbot/mixins.pyl

@@ -481,6 +481,13 @@
       },
     },
   },
+  'mac_all_arch': {
+    'swarming': {
+      'dimensions': {
+        'cpu': 'x86-64|arm64',
+      },
+    },
+  },
   'mac_mini_10.12': {
     'swarming': {
       'dimensions': {

testing/buildbot/waterfalls.pyl

@@ -1659,6 +1659,9 @@
         },
       },
       'mac-rel-swarming': {
+        'mixins': [
+          'mac_all_arch',
+        ],
         'test_suites': {
            'gtest_tests': 'chromium_swarm_desktop_gtests',
         },