Add Leak Detector to chromium.fyi.json

This CL depends on https://chromium-review.googlesource.com/c/chromium/src/+/721402.

Bug: 777765
Change-Id: I887fc1db28c8b048a334bfe936635b29de431280
Reviewed-on: https://chromium-review.googlesource.com/743164
Commit-Queue: Yuzu Saijo <yuzus@chromium.org>
Reviewed-by: Dirk Pranke <dpranke@chromium.org>
Cr-Commit-Position: refs/heads/master@{#521631}

testing/buildbot/chromium.fyi.json

@@ -4379,6 +4379,31 @@
       "all"
     ]
   },
+  "Leak Detection Linux": {
+    "isolated_scripts": [
+      {
+        "args": [
+          "memory.leak_detection",
+          "--upload-results",
+          "--output-format=histograms",
+          "--output-format=json-test-results",
+          "--browser=default"
+        ],
+        "isolate_name": "telemetry_perf_tests",
+        "name": "memory.leak_detection",
+        "override_compile_targets": [
+          "telemetry_perf_tests"
+        ],
+        "swarming": {
+          "can_use_on_swarming_builders": true,
+          "expiration": 36000,
+          "hard_timeout": 10800,
+          "ignore_task_failure": false,
+          "io_timeout": 3600
+        }
+      }
+    ]
+  },
   "Linux ARM": {
     "gtest_tests": [
       {