metrics: Add leak detector controller in Chrome OS metrics system

chrome/browser/BUILD.gn

Index: chrome/browser/BUILD.gn
diff --git a/chrome/browser/BUILD.gn b/chrome/browser/BUILD.gn
index 47f1ce028068b6598b3d4e305cd1e3be56a058fa..561696b799a3fa71910d113e062d810fe7b0943b 100644
--- a/chrome/browser/BUILD.gn
+++ b/chrome/browser/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/crypto.gni")
 import("//build/config/features.gni")
@@ -596,6 +597,14 @@ source_set("browser") {
     ]
   }
 
+  if (is_chromeos && enable_leak_detector) {
+    sources += [
+      "metrics/leak_detector_controller.cc",
+      "metrics/leak_detector_controller.h",
+    ]
+    deps += [ "//components/metrics:leak_detector" ]
+  }
+
   if (use_cups) {
     configs += [ "//printing:cups" ]
   }