Increase blink_web_tests shards for Linux Tests (dbg)(1)

Currently the shards runtime are very close to 1 hour limit and has
caused several shards timed out.

Bug: 1228440
Change-Id: I872fcad3b960135b51fcb32539f5962c1c4f94ad
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3024606
Reviewed-by: Stephen Martinis <martiniss@chromium.org>
Reviewed-by: Sven Zheng <svenzheng@chromium.org>
Commit-Queue: Sven Zheng <svenzheng@chromium.org>
Cr-Commit-Position: refs/heads/master@{#901148}
diff --git a/testing/buildbot/test_suite_exceptions.pyl b/testing/buildbot/test_suite_exceptions.pyl
index 3c8f996c..1a4c01a 100644
--- a/testing/buildbot/test_suite_exceptions.pyl
+++ b/testing/buildbot/test_suite_exceptions.pyl
@@ -241,7 +241,7 @@
           '--debug',
         ],
         'swarming': {
-          'shards': 25,
+          'shards': 30,
         },
       },
       'Mac10.11 Tests': {