metrics: Add leak detector controller in Chrome OS metrics system

chrome/test/BUILD.gn

Index: chrome/test/BUILD.gn
diff --git a/chrome/test/BUILD.gn b/chrome/test/BUILD.gn
index ea7f8c9cdb0aa6c538a75d4bb618fbb6e2941dfe..01aaf8c3eb3dabd281e369c9f87675e1162bb77b 100644
--- a/chrome/test/BUILD.gn
+++ b/chrome/test/BUILD.gn
@@ -2,6 +2,7 @@
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
+import("//build/config/allocator.gni")
 import("//build/config/chrome_build.gni")
 import("//build/config/compiler/compiler.gni")
 import("//build/config/crypto.gni")
@@ -1878,6 +1879,9 @@ test("unit_tests") {
     ]
     sources -= [ "../browser/signin/signin_manager_unittest.cc" ]
   }
+  if (is_chromeos && enable_leak_detector) {
+    sources += [ "../browser/metrics/leak_detector_controller_unittest.cc" ]
+  }
   if (use_x11) {
     deps += [ "//ui/events/devices" ]
     data_deps += [ "//tools/xdisplaycheck" ]