Remove sync_integration_tests from Mac CQ bot

At least hundreds of tests show flakiness on CQ bot. After
some spot check, the CI bot is stable. So disable the whole
test suite on CQ.

Bug: 1131588
Change-Id: Ifa1e064ade0027a0d7f1baf508fc7b22a9acd67d
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2464022Reviewed-by: Stephen Martinis <martiniss@chromium.org>
Reviewed-by: Mikel Astiz <mastiz@chromium.org>
Commit-Queue: Sven Zheng <svenzheng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#815792}

testing/buildbot/chromium.mac.json

@@ -6560,6 +6560,9 @@
           "args": [],
           "script": "//testing/merge_scripts/standard_gtest_merge.py"
         },
+        "precommit_args": [
+          "--gtest_filter=-*"
+        ],
         "swarming": {
           "can_use_on_swarming_builders": true,
           "dimension_sets": [

testing/buildbot/test_suite_exceptions.pyl

@@ -2515,6 +2515,12 @@
           'shards': 6,
         },
       },
+      # TODO(crbug.com/1131588) Tests are flaky only on CQ.
+      'Mac10.13 Tests': {
+        'precommit_args': [
+            '--gtest_filter=-*',
+          ],
+      },
       'ToTLinuxTSan': {
         'swarming': {
           'shards': 6,