Create a histogram serialization mechanism in components/metrics

components/metrics.gypi

Index: components/metrics.gypi
diff --git a/components/metrics.gypi b/components/metrics.gypi
index e0fe84889fe14dcbc611a7e4d04047a580221611..7645a01d2855810ae7554e84fef75a362700fba8 100644
--- a/components/metrics.gypi
+++ b/components/metrics.gypi
@@ -22,6 +22,14 @@
         'metrics/metrics_log_manager.cc',
         'metrics/metrics_log_manager.h',
       ],
+      'conditions': [
+        ['chromeos==1', {
+          'dependencies': [
+            'metrics_export',
+            ],
+          },
+        ],
+      ],
     },
     {
       # Protobuf compiler / generator for UMA (User Metrics Analysis).
@@ -42,5 +50,18 @@
       },
       'includes': [ '../build/protoc.gypi' ],
     },
-  ],
+    {
+      'target_name': 'metrics_export',
+      'type': 'static_library',
+      'sources':[
+        'metrics/chromeos/metrics_utils.cc',
+        'metrics/chromeos/metrics_utils.h',
+        'metrics/chromeos/metric_sample.cc',
+        'metrics/chromeos/metric_sample.h',
+        ],
+      'dependencies': [
+        '../base/base.gyp:base',
+        ],
+      },
+    ],
 }