Add a field 'requires_simultaneous_shard_dispatch': True to perf trigger script.

The perf trigger script requires that all shards are dispatched simultaneously.
The go implementation of 'swarming.py trigger' requires one invocation for each
shard. This CL adds a field to the perf trigger script dictionary so that the
recipe engine can correctly handle the different dispatch requirements.

Bug: 926987
Change-Id: I52b739afc707dd77acd012ca483f5ce27dd7bbb7
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1501950Reviewed-by: Caleb Rouleau <crouleau@chromium.org>
Reviewed-by: Stephen Martinis <martiniss@chromium.org>
Commit-Queue: Erik Chen <erikchen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#637843}

testing/buildbot/chromium.perf.fyi.json

@@ -39,6 +39,7 @@
             "--multiple-dimension-script-verbose",
             "True"
           ],
+          "requires_simultaneous_shard_dispatch": true,
           "script": "//testing/trigger_scripts/perf_device_trigger.py"
         }
       },
@@ -80,6 +81,7 @@
             "--multiple-dimension-script-verbose",
             "True"
           ],
+          "requires_simultaneous_shard_dispatch": true,
           "script": "//testing/trigger_scripts/perf_device_trigger.py"
         }
       }
@@ -125,6 +127,7 @@
             "--multiple-dimension-script-verbose",
             "True"
           ],
+          "requires_simultaneous_shard_dispatch": true,
           "script": "//testing/trigger_scripts/perf_device_trigger.py"
         }
       }
@@ -170,6 +173,7 @@
             "--multiple-dimension-script-verbose",
             "True"
           ],
+          "requires_simultaneous_shard_dispatch": true,
           "script": "//testing/trigger_scripts/perf_device_trigger.py"
         }
       }
@@ -215,6 +219,7 @@
             "--multiple-dimension-script-verbose",
             "True"
           ],
+          "requires_simultaneous_shard_dispatch": true,
           "script": "//testing/trigger_scripts/perf_device_trigger.py"
         }
       }
@@ -260,6 +265,7 @@
             "--multiple-dimension-script-verbose",
             "True"
           ],
+          "requires_simultaneous_shard_dispatch": true,
           "script": "//testing/trigger_scripts/perf_device_trigger.py"
         }
       }

tools/perf/core/perf_data_generator.py

@@ -892,6 +892,7 @@ def validate_tests(waterfall, waterfall_file, fyi_waterfall_file,
 
 def add_common_test_properties(test_entry):
   test_entry['trigger_script'] = {
+      'requires_simultaneous_shard_dispatch': True,
       'script': '//testing/trigger_scripts/perf_device_trigger.py',
       'args': [
           '--multiple-dimension-script-verbose',

tools/perf/core/perf_data_generator_unittest.py

@@ -78,6 +78,7 @@ class PerfDataGeneratorTest(unittest.TestCase):
             '--multiple-dimension-script-verbose',
             'True'
           ],
+          'requires_simultaneous_shard_dispatch': True,
           'script': '//testing/trigger_scripts/perf_device_trigger.py'
         },
         'merge': {
@@ -128,6 +129,7 @@ class PerfDataGeneratorTest(unittest.TestCase):
             '--multiple-dimension-script-verbose',
             'True'
           ],
+          'requires_simultaneous_shard_dispatch': True,
           'script': '//testing/trigger_scripts/perf_device_trigger.py'
         },
         'merge': {
@@ -176,6 +178,7 @@ class PerfDataGeneratorTest(unittest.TestCase):
             '--multiple-dimension-script-verbose',
             'True'
           ],
+          'requires_simultaneous_shard_dispatch': True,
           'script': '//testing/trigger_scripts/perf_device_trigger.py'
         },
         'merge': {