Change browser type for leak fyi bot

This CL changes the browser type for leak detection fyi bot.


Bug: 763280
Change-Id: I0ffe2e1ec2f463037dc5ecb9f40ca4a4a806ff5e
Reviewed-on: https://chromium-review.googlesource.com/818671Reviewed-by: Ned Nguyen <nednguyen@google.com>
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Commit-Queue: Yuzu Saijo <yuzus@chromium.org>
Cr-Commit-Position: refs/heads/master@{#523997}

testing/buildbot/chromium.fyi.json

@@ -4034,7 +4034,8 @@
           "--upload-results",
           "--output-format=histograms",
           "--output-format=json-test-results",
-          "--browser=default"
+          "--browser=release",
+          "--xvfb"
         ],
         "isolate_name": "telemetry_perf_tests",
         "name": "memory.leak_detection",

testing/buildbot/test_suites.pyl

@@ -896,7 +896,8 @@
         '--upload-results',
         '--output-format=histograms',
         '--output-format=json-test-results',
-        '--browser=default',
+        '--browser=release',
+        '--xvfb'
       ],
       'isolate_name': 'telemetry_perf_tests',
       'override_compile_targets': [