Mac10.13 Tests: drop browser_tests to experimental and disable window server suspects.

TBR=ellyjones@chromium.org

Bug: 767397
Change-Id: I88764b5dad273ec9dbea975cc6e97ce799ce6fe1
Reviewed-on: https://chromium-review.googlesource.com/1100296Reviewed-by: John Budorick <jbudorick@chromium.org>
Commit-Queue: John Budorick <jbudorick@chromium.org>
Cr-Commit-Position: refs/heads/master@{#567119}

testing/buildbot/chromium.mac.json

@@ -1549,6 +1549,10 @@
         "test": "boringssl_ssl_tests"
       },
       {
+        "args": [
+          "--test-launcher-filter-file=../../testing/buildbot/filters/mac_window_server_killers.browser_tests.filter"
+        ],
+        "experiment_percentage": 100,
         "swarming": {
           "can_use_on_swarming_builders": true,
           "shards": 10

testing/buildbot/test_suite_exceptions.pyl

@@ -243,6 +243,7 @@
           'shards': 5,
         },
       },
+      # chromium.mac
       'Mac10.11 Tests': {
         'args': [
           '--test-launcher-filter-file=../../testing/buildbot/filters/mac_window_server_killers.browser_tests.filter',
@@ -253,6 +254,12 @@
           '--test-launcher-filter-file=../../testing/buildbot/filters/mac_window_server_killers.browser_tests.filter',
         ],
       },
+      'Mac10.13 Tests': {
+        'args': [
+          '--test-launcher-filter-file=../../testing/buildbot/filters/mac_window_server_killers.browser_tests.filter',
+        ],
+        'experiment_percentage': 100,
+      },
       # chromium.memory
       'Linux ASan LSan Tests (1)': {
         # These are very slow on the ASAN trybot for some reason.