Increase sharding on "WebKit Linux layout_ng_disabled Builder"

The trybot is timing out sometimes in builds. This should fix those
issues.

The trybot roughly looks like it has a max of 100 builds a day. Each
task has 1 minute of overhead, so this will generate 8 * 1 * 100 = 800
additional minutes of overhead per day, which should be pretty minor in
the grand scheme of things.

R=gatong, gbeaty

Bug: 1182334
Change-Id: If410211e226522553a10754111ecdc0f0ad76073
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2720661
Reviewed-by: Garrett Beaty <[email protected]>
Reviewed-by: Gary Tong <[email protected]>
Commit-Queue: Stephen Martinis <[email protected]>
Cr-Commit-Position: refs/heads/master@{#858794}
diff --git a/testing/buildbot/chromium.fyi.json b/testing/buildbot/chromium.fyi.json
index 2ea2841b..5a3d8a9 100644
--- a/testing/buildbot/chromium.fyi.json
+++ b/testing/buildbot/chromium.fyi.json
@@ -2303,7 +2303,7 @@
           ],
           "hard_timeout": 900,
           "service_account": "[email protected]",
-          "shards": 12
+          "shards": 20
         },
         "test_id_prefix": "ninja://:blink_web_tests/"
       }
diff --git a/testing/buildbot/test_suite_exceptions.pyl b/testing/buildbot/test_suite_exceptions.pyl
index c36a00f..b0f059c 100644
--- a/testing/buildbot/test_suite_exceptions.pyl
+++ b/testing/buildbot/test_suite_exceptions.pyl
@@ -328,6 +328,9 @@
         'args': [
           '--additional-driver-flag=--disable-blink-features=LayoutNG',
         ],
+        'swarming': {
+          'shards': 20,
+        },
       },
       'Win10 Tests x64': {
         'args': [