metrics: Add leak detector controller in Chrome OS metrics system

components/metrics.gypi

Index: components/metrics.gypi
diff --git a/components/metrics.gypi b/components/metrics.gypi
index b90ebc6306570a73521635f07e5e3e1ef4d0f08c..f8cfb81ae5a5d394f83de4723610fa519ad7951d 100644
--- a/components/metrics.gypi
+++ b/components/metrics.gypi
@@ -102,6 +102,18 @@
       ],
     },
     {
+      # GN version: //components/metrics:metrics_flags
+      'target_name': 'metrics_flags',
+      'includes': [
+        '../build/buildflag_header.gypi',
+        'metrics/leak_detector/leak_detector.gypi',
+      ],
+      'variables': {
+        'buildflag_header_path': 'metrics/metrics_flags.h',
+        'buildflag_flags': [ 'ENABLE_LEAK_DETECTOR=<(enable_leak_detector)' ],
+      },
+    },
+    {
       # GN version: //components/metrics:net
       'target_name': 'metrics_net',
       'type': 'static_library',
@@ -259,6 +271,8 @@
             'metrics/leak_detector/custom_allocator.h',
             'metrics/leak_detector/leak_analyzer.cc',
             'metrics/leak_detector/leak_analyzer.h',
+            'metrics/leak_detector/leak_detector.cc',
+            'metrics/leak_detector/leak_detector.h',
             'metrics/leak_detector/leak_detector_impl.cc',
             'metrics/leak_detector/leak_detector_impl.h',
             'metrics/leak_detector/leak_detector_value_type.cc',