Increase shard count for all chrome_all_tast_test runs to 4.

This bumps it from 2 to 4 across every bot. This helps builders like the
amd64-generic CQ bot which runs shards with 15-17min runtimes
(https://ci.chromium.org/p/chromium/builders/try/chromeos-amd64-generic-rel/737112)
and the eve CI bot which runs shards with ~30min runtimes
(https://ci.chromium.org/p/chrome/builders/ci/chromeos-eve-chrome/12083).

Bug: None
Change-Id: I3ef9d7eaabf3d1d8085d55b4f25adc70a6fc3f03
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2622897Reviewed-by: Yuke Liao <liaoyuke@chromium.org>
Commit-Queue: Ben Pastene <bpastene@chromium.org>
Cr-Commit-Position: refs/heads/master@{#842318}

testing/buildbot/chrome.json

@@ -67,7 +67,7 @@
             ]
           },
           "service_account": "chrome-tester@chops-service-accounts.iam.gserviceaccount.com",
-          "shards": 2
+          "shards": 4
         },
         "test": "chrome_all_tast_tests",
         "test_id_prefix": "ninja://chromeos:chrome_all_tast_tests/"
@@ -287,7 +287,7 @@
             ]
           },
           "service_account": "chrome-tester@chops-service-accounts.iam.gserviceaccount.com",
-          "shards": 2
+          "shards": 4
         },
         "test": "chrome_all_tast_tests",
         "test_id_prefix": "ninja://chromeos:chrome_all_tast_tests/"
@@ -1333,7 +1333,7 @@
             ]
           },
           "service_account": "chrome-tester@chops-service-accounts.iam.gserviceaccount.com",
-          "shards": 2
+          "shards": 4
         },
         "test": "chrome_all_tast_tests",
         "test_id_prefix": "ninja://chromeos:chrome_all_tast_tests/"
@@ -2379,7 +2379,7 @@
             ]
           },
           "service_account": "chrome-tester@chops-service-accounts.iam.gserviceaccount.com",
-          "shards": 2
+          "shards": 4
         },
         "test": "chrome_all_tast_tests",
         "test_id_prefix": "ninja://chromeos:chrome_all_tast_tests/"
@@ -3425,7 +3425,7 @@
             ]
           },
           "service_account": "chrome-tester@chops-service-accounts.iam.gserviceaccount.com",
-          "shards": 2
+          "shards": 4
         },
         "test": "chrome_all_tast_tests",
         "test_id_prefix": "ninja://chromeos:chrome_all_tast_tests/"
@@ -4471,7 +4471,7 @@
             ]
           },
           "service_account": "chrome-tester@chops-service-accounts.iam.gserviceaccount.com",
-          "shards": 2
+          "shards": 4
         },
         "test": "chrome_all_tast_tests",
         "test_id_prefix": "ninja://chromeos:chrome_all_tast_tests/"
@@ -5389,7 +5389,7 @@
           ],
           "idempotent": false,
           "service_account": "chrome-tester@chops-service-accounts.iam.gserviceaccount.com",
-          "shards": 2
+          "shards": 4
         },
         "test": "chrome_all_tast_tests",
         "test_id_prefix": "ninja://chromeos:chrome_all_tast_tests/",
@@ -5541,7 +5541,7 @@
           ],
           "idempotent": false,
           "service_account": "chrome-tester@chops-service-accounts.iam.gserviceaccount.com",
-          "shards": 2
+          "shards": 4
         },
         "test": "chrome_all_tast_tests",
         "test_id_prefix": "ninja://chromeos:chrome_all_tast_tests/",
@@ -5693,7 +5693,7 @@
           ],
           "idempotent": false,
           "service_account": "chrome-tester@chops-service-accounts.iam.gserviceaccount.com",
-          "shards": 2
+          "shards": 4
         },
         "test": "chrome_all_tast_tests",
         "test_id_prefix": "ninja://chromeos:chrome_all_tast_tests/",
@@ -5845,7 +5845,7 @@
           ],
           "idempotent": false,
           "service_account": "chrome-tester@chops-service-accounts.iam.gserviceaccount.com",
-          "shards": 2
+          "shards": 4
         },
         "test": "chrome_all_tast_tests",
         "test_id_prefix": "ninja://chromeos:chrome_all_tast_tests/",
@@ -5997,7 +5997,7 @@
           ],
           "idempotent": false,
           "service_account": "chrome-tester@chops-service-accounts.iam.gserviceaccount.com",
-          "shards": 2
+          "shards": 4
         },
         "test": "chrome_all_tast_tests",
         "test_id_prefix": "ninja://chromeos:chrome_all_tast_tests/",
@@ -6149,7 +6149,7 @@
           ],
           "idempotent": false,
           "service_account": "chrome-tester@chops-service-accounts.iam.gserviceaccount.com",
-          "shards": 2
+          "shards": 4
         },
         "test": "chrome_all_tast_tests",
         "test_id_prefix": "ninja://chromeos:chrome_all_tast_tests/",
@@ -6233,7 +6233,7 @@
           ],
           "idempotent": false,
           "service_account": "chrome-tester@chops-service-accounts.iam.gserviceaccount.com",
-          "shards": 2
+          "shards": 4
         },
         "test": "chrome_all_tast_tests",
         "test_id_prefix": "ninja://chromeos:chrome_all_tast_tests/",
@@ -6317,7 +6317,7 @@
           ],
           "idempotent": false,
           "service_account": "chrome-tester@chops-service-accounts.iam.gserviceaccount.com",
-          "shards": 2
+          "shards": 4
         },
         "test": "chrome_all_tast_tests",
         "test_id_prefix": "ninja://chromeos:chrome_all_tast_tests/",
@@ -6401,7 +6401,7 @@
           ],
           "idempotent": false,
           "service_account": "chrome-tester@chops-service-accounts.iam.gserviceaccount.com",
-          "shards": 2
+          "shards": 4
         },
         "test": "chrome_all_tast_tests",
         "test_id_prefix": "ninja://chromeos:chrome_all_tast_tests/",
@@ -6485,7 +6485,7 @@
           ],
           "idempotent": false,
           "service_account": "chrome-tester@chops-service-accounts.iam.gserviceaccount.com",
-          "shards": 2
+          "shards": 4
         },
         "test": "chrome_all_tast_tests",
         "test_id_prefix": "ninja://chromeos:chrome_all_tast_tests/",

testing/buildbot/chromium.chromiumos.json

@@ -232,7 +232,7 @@
             ]
           },
           "service_account": "chromium-tester@chops-service-accounts.iam.gserviceaccount.com",
-          "shards": 2
+          "shards": 4
         },
         "test": "chrome_all_tast_tests",
         "test_id_prefix": "ninja://chromeos:chrome_all_tast_tests/"
@@ -1208,7 +1208,7 @@
           ],
           "idempotent": false,
           "service_account": "chromium-tester@chops-service-accounts.iam.gserviceaccount.com",
-          "shards": 2
+          "shards": 4
         },
         "test": "chrome_all_tast_tests",
         "test_id_prefix": "ninja://chromeos:chrome_all_tast_tests/",

testing/buildbot/internal.chromeos.fyi.json

@@ -52,7 +52,7 @@
           ],
           "idempotent": false,
           "service_account": "chrome-tester@chops-service-accounts.iam.gserviceaccount.com",
-          "shards": 2
+          "shards": 4
         },
         "test": "chrome_all_tast_tests",
         "test_id_prefix": "ninja://chromeos:chrome_all_tast_tests/"
@@ -258,7 +258,7 @@
             ]
           },
           "service_account": "chrome-tester@chops-service-accounts.iam.gserviceaccount.com",
-          "shards": 2
+          "shards": 4
         },
         "test": "chrome_all_tast_tests",
         "test_id_prefix": "ninja://chromeos:chrome_all_tast_tests/"
@@ -1173,7 +1173,7 @@
           ],
           "idempotent": false,
           "service_account": "chrome-tester@chops-service-accounts.iam.gserviceaccount.com",
-          "shards": 2
+          "shards": 4
         },
         "test": "chrome_all_tast_tests",
         "test_id_prefix": "ninja://chromeos:chrome_all_tast_tests/",

testing/buildbot/test_suites.pyl

@@ -458,7 +458,7 @@
       'chrome_all_tast_tests': {
         'swarming': {
           'idempotent': False,  # https://crbug.com/923426#c27
-          'shards': 2,
+          'shards': 4,
         },
         'resultdb': {
           'enable': True,