[ios/infra] move xcode-parallelization to testing/buildbot

Not all EG2 tests run with xcode-parallelization. This is an arg
that's primiarily used with simulators. Downstream, eg2 tests
are also run on devices.

Because simulators are defined in testing/buildbot, and because
the xcode-parallelization arg is bound to platform and version
(both defined by simulators), we move this arg down to testing.

* Introduced support for mixins one level above variants such that
a mixin defined here applies to all variants below.
* Removed the --xcode-parallelization arg in the GN EG2 iOS
template.
* Added xcode-parallelization for all test targets that ran
through the eg2 target upstream.

Bug: 912681
Change-Id: Ie5cb45a14be0ecbb6fb64b7c8af6eea6f49df94c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2364031
Commit-Queue: Dirk Pranke <dpranke@google.com>
Reviewed-by: Dirk Pranke <dpranke@google.com>
Reviewed-by: Garrett Beaty <gbeaty@chromium.org>
Cr-Commit-Position: refs/heads/master@{#800180}

build/config/ios/ios_test_runner_wrapper.gni

@@ -134,6 +134,7 @@ template("ios_test_runner_wrapper") {
       "//testing/test_env.py",
       "//.vpython",
       "//ios/build/bots/scripts/",
+      "//testing/test_env.py",
     ]
   }
 }

ios/third_party/earl_grey2/ios_eg2_test.gni

@@ -122,10 +122,6 @@ template("ios_eg2_test") {
       "--host-app",
       "@WrappedPath(${_root_build_dir}/${xcode_test_application_name}.app)",
     ]
-
-    # All EG2 tests require xcode-parallelization. EG2 doesn't use xctest, so we
-    # leave undefined
-    executable_args += [ "--xcode-parallelization" ]
   }
 }
 

testing/buildbot/generate_buildbot_json.py

@@ -1006,7 +1006,7 @@ class BBJSONGenerator(object):
         full_suite.update(suite)
       compound_suites[name] = full_suite
 
-  def resolve_variants(self, basic_test_definition, variants):
+  def resolve_variants(self, basic_test_definition, variants, mixins):
     """ Merge variant-defined configurations to each test case definition in a
     test suite.
 
@@ -1044,7 +1044,7 @@ class BBJSONGenerator(object):
         cloned_config['args'] = (cloned_config.get('args', []) +
                                  cloned_variant.get('args', []))
         cloned_config['mixins'] = (cloned_config.get('mixins', []) +
-                                   cloned_variant.get('mixins', []))
+                                   cloned_variant.get('mixins', []) + mixins)
 
         basic_swarming_def = cloned_config.get('swarming', {})
         variant_swarming_def = cloned_variant.get('swarming', {})
@@ -1089,8 +1089,10 @@ class BBJSONGenerator(object):
         basic_test_def = copy.deepcopy(basic_suites[test_suite])
 
         if 'variants' in mtx_test_suite_config:
+          mixins = mtx_test_suite_config.get('mixins', [])
           result = self.resolve_variants(basic_test_def,
-                                         mtx_test_suite_config['variants'])
+                                         mtx_test_suite_config['variants'],
+                                         mixins)
           full_suite.update(result)
       matrix_compound_suites[test_name] = full_suite
 

testing/buildbot/generate_buildbot_json_unittest.py

@@ -5284,6 +5284,7 @@ MATRIX_COMPOUND_TARGETS_MIXINS = """\
   'matrix_compound_suites': {
     'matrix_tests': {
       'foo_tests': {
+        'mixins': [ 'random_mixin' ],
         'variants': [
           {
             'identifier': 'args',
@@ -5588,7 +5589,8 @@ MATRIX_TARGET_DICT_MERGE_OUTPUT_MIXINS = """\
           "can_use_on_swarming_builders": true,
           "value": "test"
         },
-        "test": "mixins_test"
+        "test": "mixins_test",
+        "value": "random"
       },
       {
         "args": [],
@@ -5606,7 +5608,8 @@ MATRIX_TARGET_DICT_MERGE_OUTPUT_MIXINS = """\
           ],
           "value": "test"
         },
-        "test": "mixins_test"
+        "test": "mixins_test",
+        "value": "random"
       },
       {
         "args": [],
@@ -5625,7 +5628,8 @@ MATRIX_TARGET_DICT_MERGE_OUTPUT_MIXINS = """\
           ],
           "value": "test"
         },
-        "test": "mixins_test"
+        "test": "mixins_test",
+        "value": "random"
       }
     ]
   }

testing/buildbot/mixins.pyl

@@ -980,4 +980,11 @@
       ],
     },
   },
+  'xcode_parallelization': {
+    '$mixin_append': {
+      'args': [
+        '--xcode-parallelization',
+      ],
+    },
+  },
 }

testing/buildbot/test_suites.pyl

@@ -5541,6 +5541,7 @@
         ],
       },
       'ios_eg2_tests': {
+        'mixins': ['xcode_parallelization'],
         'variants': [
           'SIM_IPHONE_X_14_0',
           'SIM_IPHONE_7_14_0',
@@ -5549,6 +5550,7 @@
         ]
       },
       'ios_eg2_cq_tests': {
+        'mixins': ['xcode_parallelization'],
         'variants': [
           'SIM_IPHONE_7_14_0',
           'SIM_IPHONE_X_14_0',
@@ -5577,6 +5579,7 @@
         ],
       },
       'ios_eg2_tests': {
+        'mixins': ['xcode_parallelization'],
         'variants': [
           # 14.0 Sims
           'SIM_IPHONE_7_14_0',
@@ -5593,6 +5596,7 @@
         ]
       },
       'ios_eg2_cq_tests': {
+        'mixins': ['xcode_parallelization'],
         'variants': [
           # 14.0 Sims
           'SIM_IPHONE_X_14_0',
@@ -5663,6 +5667,7 @@
         ],
       },
       'ios_eg2_cq_tests': {
+        'mixins': ['xcode_parallelization'],
         'variants': [
           'SIM_IPHONE_6S_12_4',
           'SIM_IPAD_AIR_2_12_4',
@@ -5672,6 +5677,7 @@
         ],
       },
       'ios_eg2_tests': {
+        'mixins': ['xcode_parallelization'],
         'variants': [
           'SIM_IPAD_AIR_2_12_4',
           'SIM_IPHONE_X_12_4',
@@ -5701,6 +5707,7 @@
 
     'ios_simulator_full_configs_test': {
       'ios_eg2_tests': {
+        'mixins': ['xcode_parallelization'],
         'variants': [
           'SIM_IPAD_AIR_2_12_4',
           'SIM_IPHONE_X_12_4',
@@ -5710,6 +5717,7 @@
         ]
       },
       'ios_eg2_cq_tests': {
+        'mixins': ['xcode_parallelization'],
         'variants': [
           'SIM_IPAD_AIR_2_12_4',
           'SIM_IPHONE_7_13_6',
@@ -5725,11 +5733,13 @@
         ]
       },
       'ios_eg2_cq_tests': {
+        'mixins': ['xcode_parallelization'],
         'variants': [
           'SIM_IPAD_AIR_2_13_6',
         ]
       },
       'ios_eg2_tests': {
+        'mixins': ['xcode_parallelization'],
         'variants': [
           'SIM_IPAD_AIR_2_13_6',
         ]
@@ -5749,6 +5759,7 @@
         ]
       },
       'ios_eg2_cq_tests': {
+        'mixins': ['xcode_parallelization'],
         'variants': [
           'SIM_IPHONE_6S_12_4',
           'SIM_IPHONE_6S_13_6',
@@ -5772,12 +5783,14 @@
         ]
       },
       'ios_eg2_cq_tests': {
+        'mixins': ['xcode_parallelization'],
         'variants': [
           'SIM_IPHONE_X_13_5',
           'SIM_IPAD_AIR_2_13_5',
         ]
       },
       'ios_eg2_tests': {
+        'mixins': ['xcode_parallelization'],
         'variants': [
           'SIM_IPHONE_X_13_5',
           'SIM_IPAD_AIR_2_13_5',