Revert "[testing] switch to use xenial for swarming test"

This reverts commit bb8a36eb.

Reason for revert: Created too much load on too-small Xenial
pool, resulting in large pending test shard times, resulting
in long builds, resulting in pending times, resulting in even
longer builds due to cold caches, resulting in even longer
pending times.

Original change's description:
> [testing] switch to use xenial for swarming test
> 
> This CL switches to use xenial for test as many as possible.
> 
> Sheriff:
> If this broke some ci/fyi builder, feel free to revert this.
> 
> TBR=jbudorick
> 
> Bug: 954450
> Change-Id: I98abfb50bb10ca3eeec0e23d197fe7672c8acc95
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1689513
> Reviewed-by: Takuto Ikuta <tikuta@chromium.org>
> Commit-Queue: Takuto Ikuta <tikuta@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#675527}

TBR=yyanagisawa@chromium.org,tikuta@chromium.org,jbudorick@chromium.org

Change-Id: I1244abdfa1cf627c7f9effa3048ccf8ed53091b8
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 954450, 982335
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1692035Reviewed-by: John Budorick <jbudorick@chromium.org>
Reviewed-by: Aaron Gable <agable@chromium.org>
Commit-Queue: John Budorick <jbudorick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#675722}

testing/buildbot/chromium.goma.json

@@ -21,7 +21,7 @@
           "can_use_on_swarming_builders": true,
           "dimension_sets": [
             {
-              "os": "Ubuntu-16.04"
+              "os": "Ubuntu-14.04"
             }
           ]
         },
@@ -36,7 +36,7 @@
           "can_use_on_swarming_builders": true,
           "dimension_sets": [
             {
-              "os": "Ubuntu-16.04"
+              "os": "Ubuntu-14.04"
             }
           ]
         },
@@ -58,7 +58,7 @@
           "can_use_on_swarming_builders": true,
           "dimension_sets": [
             {
-              "os": "Ubuntu-16.04"
+              "os": "Ubuntu-14.04"
             }
           ]
         },
@@ -73,7 +73,7 @@
           "can_use_on_swarming_builders": true,
           "dimension_sets": [
             {
-              "os": "Ubuntu-16.04"
+              "os": "Ubuntu-14.04"
             }
           ]
         },
@@ -95,7 +95,7 @@
           "can_use_on_swarming_builders": true,
           "dimension_sets": [
             {
-              "os": "Ubuntu-16.04"
+              "os": "Ubuntu-14.04"
             }
           ]
         },
@@ -110,7 +110,7 @@
           "can_use_on_swarming_builders": true,
           "dimension_sets": [
             {
-              "os": "Ubuntu-16.04"
+              "os": "Ubuntu-14.04"
             }
           ]
         },
@@ -132,7 +132,7 @@
           "can_use_on_swarming_builders": true,
           "dimension_sets": [
             {
-              "os": "Ubuntu-16.04"
+              "os": "Ubuntu-14.04"
             }
           ]
         },
@@ -147,7 +147,7 @@
           "can_use_on_swarming_builders": true,
           "dimension_sets": [
             {
-              "os": "Ubuntu-16.04"
+              "os": "Ubuntu-14.04"
             }
           ]
         },
@@ -169,7 +169,7 @@
           "can_use_on_swarming_builders": true,
           "dimension_sets": [
             {
-              "os": "Ubuntu-16.04"
+              "os": "Ubuntu-14.04"
             }
           ]
         },
@@ -184,7 +184,7 @@
           "can_use_on_swarming_builders": true,
           "dimension_sets": [
             {
-              "os": "Ubuntu-16.04"
+              "os": "Ubuntu-14.04"
             }
           ]
         },

testing/buildbot/chromium.webrtc.fyi.json

@@ -146,7 +146,7 @@
           "dimension_sets": [
             {
               "cpu": "x86-64",
-              "os": "Ubuntu-16.04"
+              "os": "Ubuntu-14.04"
             }
           ]
         },
@@ -167,7 +167,7 @@
           "dimension_sets": [
             {
               "cpu": "x86-64",
-              "os": "Ubuntu-16.04"
+              "os": "Ubuntu-14.04"
             }
           ]
         },
@@ -186,7 +186,7 @@
           "dimension_sets": [
             {
               "cpu": "x86-64",
-              "os": "Ubuntu-16.04"
+              "os": "Ubuntu-14.04"
             }
           ]
         },
@@ -208,7 +208,7 @@
           "dimension_sets": [
             {
               "cpu": "x86-64",
-              "os": "Ubuntu-16.04"
+              "os": "Ubuntu-14.04"
             }
           ]
         },
@@ -227,7 +227,7 @@
           "dimension_sets": [
             {
               "cpu": "x86-64",
-              "os": "Ubuntu-16.04"
+              "os": "Ubuntu-14.04"
             }
           ]
         },
@@ -243,7 +243,7 @@
           "dimension_sets": [
             {
               "cpu": "x86-64",
-              "os": "Ubuntu-16.04"
+              "os": "Ubuntu-14.04"
             }
           ]
         },
@@ -262,7 +262,7 @@
           "dimension_sets": [
             {
               "cpu": "x86-64",
-              "os": "Ubuntu-16.04"
+              "os": "Ubuntu-14.04"
             }
           ]
         },

testing/buildbot/chromium.webrtc.json

@@ -107,7 +107,7 @@
           "can_use_on_swarming_builders": true,
           "dimension_sets": [
             {
-              "os": "Ubuntu-16.04"
+              "os": "Ubuntu-14.04"
             }
           ]
         },
@@ -127,7 +127,7 @@
           "can_use_on_swarming_builders": true,
           "dimension_sets": [
             {
-              "os": "Ubuntu-16.04"
+              "os": "Ubuntu-14.04"
             }
           ]
         },
@@ -161,7 +161,7 @@
           "can_use_on_swarming_builders": true,
           "dimension_sets": [
             {
-              "os": "Ubuntu-16.04"
+              "os": "Ubuntu-14.04"
             }
           ]
         },
@@ -182,7 +182,7 @@
           "can_use_on_swarming_builders": true,
           "dimension_sets": [
             {
-              "os": "Ubuntu-16.04"
+              "os": "Ubuntu-14.04"
             }
           ]
         },
@@ -203,7 +203,7 @@
           "can_use_on_swarming_builders": true,
           "dimension_sets": [
             {
-              "os": "Ubuntu-16.04"
+              "os": "Ubuntu-14.04"
             }
           ]
         },
@@ -221,7 +221,7 @@
           "can_use_on_swarming_builders": true,
           "dimension_sets": [
             {
-              "os": "Ubuntu-16.04"
+              "os": "Ubuntu-14.04"
             }
           ]
         },
@@ -236,7 +236,7 @@
           "can_use_on_swarming_builders": true,
           "dimension_sets": [
             {
-              "os": "Ubuntu-16.04"
+              "os": "Ubuntu-14.04"
             }
           ]
         },
@@ -254,7 +254,7 @@
           "can_use_on_swarming_builders": true,
           "dimension_sets": [
             {
-              "os": "Ubuntu-16.04"
+              "os": "Ubuntu-14.04"
             }
           ]
         },

testing/buildbot/waterfalls.pyl

@@ -44,8 +44,6 @@
         ],
         'mixins': [
           'chrome-swarming-pool',
-          # TODO(crbug.com/954450): Switch to xenial when chrome-swarming has
-          # xenial bots.
           'linux-trusty',
         ],
         'test_suites': {
@@ -112,7 +110,7 @@
       'linux-archive-rel': {
         'mixins': [
           'linux-archive-rel-args',
-          'linux-xenial',
+          'linux-trusty',
         ],
         'additional_compile_targets': [
           'all',
@@ -972,7 +970,7 @@
       },
       'UBSanVptr Linux': {
         'mixins': [
-          'linux-xenial',
+          'linux-trusty',
         ],
         'test_suites': {
           # no "_and_gl":gl_unittests doesn't pass yet,
@@ -1299,7 +1297,7 @@
       },
       'Linux Builder Goma Canary': {
         'mixins': [
-          'linux-xenial',
+          'linux-trusty',
         ],
         'additional_compile_targets': [
           'all',
@@ -1310,7 +1308,7 @@
       },
       'Linux Viz': {
         'mixins': [
-          'linux-xenial',
+          'linux-trusty',
         ],
         'additional_compile_targets': [
           'all',
@@ -1321,7 +1319,7 @@
       },
       'Linux x64 Goma Canary (clobber)': {
         'mixins': [
-          'linux-xenial',
+          'linux-trusty',
         ],
         'additional_compile_targets': [
           'all',
@@ -1332,7 +1330,7 @@
       },
       'Linux x64 Goma Canary LocalOutputCache': {
         'mixins': [
-          'linux-xenial',
+          'linux-trusty',
         ],
         'additional_compile_targets': [
           'all',
@@ -1409,7 +1407,7 @@
       },
       'Mojo Linux': {
         'mixins': [
-          'linux-xenial',
+          'linux-trusty',
         ],
         'test_suites': {
           'gtest_tests': 'mojo_linux_gtests',
@@ -1436,7 +1434,7 @@
       },
       'VR Linux': {
         'mixins': [
-          'linux-xenial',
+          'linux-trusty',
         ],
         'additional_compile_targets': [
           'vr_common_perftests',
@@ -1769,7 +1767,7 @@
       'linux-chromeos-code-coverage': {
         'mixins': [
           'code-coverage',
-          'linux-xenial',
+          'linux-trusty',
         ],
         'additional_compile_targets': [
           'gn_all',
@@ -1781,7 +1779,7 @@
       'linux-chromeos-oobe-code-coverage': {
         'mixins': [
           'code-coverage',
-          'linux-xenial',
+          'linux-trusty',
         ],
         'additional_compile_targets': [
           'gn_all',
@@ -1792,7 +1790,7 @@
       },
       'linux-chromium-tests-staging-builder': {
         'mixins': [
-          'linux-xenial',
+          'linux-trusty',
         ],
         'additional_compile_targets': [
           'all'
@@ -1803,7 +1801,7 @@
       },
       'linux-chromium-tests-staging-tests': {
         'mixins': [
-          'linux-xenial',
+          'linux-trusty',
         ],
         'test_suites': {
           'gtest_tests': 'chromium_linux_gtests',
@@ -1813,7 +1811,7 @@
       'linux-code-coverage': {
         'mixins': [
           'code-coverage',
-          'linux-xenial',
+          'linux-trusty',
         ],
         'test_suites': {
           'gtest_tests': 'chromium_linux_coverage_gtests',
@@ -1969,7 +1967,7 @@
       },
       'Chromium Linux Goma RBE Staging': {
         'mixins': [
-          'linux-xenial',
+          'linux-trusty',
         ],
         'additional_compile_targets': [
           'all',
@@ -1980,7 +1978,7 @@
       },
       'Chromium Linux Goma RBE Staging (clobber)': {
         'mixins': [
-          'linux-xenial',
+          'linux-trusty',
         ],
         'additional_compile_targets': [
           'all',
@@ -1991,7 +1989,7 @@
       },
       'Chromium Linux Goma RBE Staging (dbg)': {
         'mixins': [
-          'linux-xenial',
+          'linux-trusty',
         ],
         'additional_compile_targets': [
           'all',
@@ -2002,7 +2000,7 @@
       },
       'Chromium Linux Goma RBE Staging (dbg) (clobber)': {
         'mixins': [
-          'linux-xenial',
+          'linux-trusty',
         ],
         'additional_compile_targets': [
           'all',
@@ -2013,7 +2011,7 @@
       },
       'Chromium Linux Goma Staging': {
         'mixins': [
-          'linux-xenial',
+          'linux-trusty',
         ],
         'additional_compile_targets': [
           'all',
@@ -3262,7 +3260,7 @@
     'machines': {
       'Cast Audio Linux': {
         'mixins': [
-          'linux-xenial',
+          'linux-trusty',
         ],
         'additional_compile_targets': [
           'cast_shell',
@@ -3310,7 +3308,7 @@
       },
       'Leak Detection Linux': {
         'mixins': [
-          'linux-xenial',
+          'linux-trusty',
         ],
         'test_suites': {
           'isolated_scripts': 'leak_detection_isolated_scripts',
@@ -3318,7 +3316,7 @@
       },
       'Linux Builder': {
         'mixins': [
-          'linux-xenial',
+          'linux-trusty',
         ],
         'additional_compile_targets': [
           'all'
@@ -3342,7 +3340,7 @@
       # linux-rel or ended up not being able to fold.
       'Linux Builder Code Coverage': {
         'mixins': [
-          'linux-xenial',
+          'linux-trusty',
           'code-coverage',
         ],
         'additional_compile_targets': [
@@ -3376,7 +3374,7 @@
       # linux-rel or ended up not being able to fold.
       'Linux Tests Code Coverage': {
         'mixins': [
-          'linux-xenial',
+          'linux-trusty',
           'code-coverage',
         ],
         'test_suites': {
@@ -3412,7 +3410,7 @@
       },
       'linux-ozone-rel': {
         'mixins': [
-          'linux-xenial',
+          'linux-trusty',
         ],
         'additional_compile_targets': [
           'chrome',
@@ -3662,7 +3660,7 @@
       },
       'Linux CFI': {
         'mixins': [
-          'linux-xenial',
+          'linux-trusty',
         ],
         'test_suites': {
           'gtest_tests': 'chromium_linux_and_gl_gtests',
@@ -3670,7 +3668,7 @@
       },
       'Linux Chromium OS ASan LSan Tests (1)': {
         'mixins': [
-          'linux-xenial',
+          'linux-trusty',
         ],
         'test_suites': {
           'gtest_tests': 'linux_chromeos_gtests',
@@ -3740,7 +3738,7 @@
       },
       'WebKit Linux MSAN': {
         'mixins': [
-          'linux-trusty',
+          'linux-xenial',
         ],
         'test_suites': {
           'isolated_scripts': 'chromium_webkit_isolated_scripts',
@@ -3829,7 +3827,7 @@
       # see crbug.com/790309, crbug.com/790294, crbug.com/790286.
       'WebKit Linux ASAN': {
         'mixins': [
-          'linux-xenial',
+          'linux-trusty',
         ],
         'test_suites': {
           'isolated_scripts': 'chromium_webkit_isolated_scripts',
@@ -3837,7 +3835,7 @@
       },
       'WebKit Linux Leak': {
         'mixins': [
-          'linux-xenial',
+          'linux-trusty',
         ],
         'test_suites': {
           'isolated_scripts': 'chromium_webkit_isolated_scripts',
@@ -3896,7 +3894,7 @@
       },
       'WebRTC Chromium Linux Tester': {
         'mixins': [
-          'linux-xenial',
+          'linux-trusty',
         ],
         'test_suites': {
           'gtest_tests': 'webrtc_chromium_tests_with_baremetal_tests',
@@ -3995,7 +3993,7 @@
       'WebRTC Chromium FYI Linux Tester': {
         'mixins': [
           'x86-64',
-          'linux-xenial',
+          'linux-trusty',
         ],
         'test_suites': {
           'gtest_tests': 'webrtc_chromium_gtests',
@@ -4158,7 +4156,7 @@
     'machines': {
       'Linux - Future': {
         'mixins': [
-          'linux-xenial',
+          'linux-trusty',
         ],
         'test_suites': {
           'gtest_tests': 'client_v8_chromium_gtests',
@@ -4167,7 +4165,7 @@
       },
       'Linux - Future (dbg)': {
         'mixins': [
-          'linux-xenial',
+          'linux-trusty',
         ],
         'test_suites': {
           'gtest_tests': 'client_v8_chromium_gtests',
@@ -4324,7 +4322,7 @@
       'linux-coverage-rel': {
         'mixins': [
           'code-coverage',
-          'linux-xenial',
+          'linux-trusty',
         ],
         'test_suites': {
           'gtest_tests': 'chromium_linux_coverage_gtests',