Create a histogram serialization mechanism in components/metrics

base/base.gypi

Index: base/base.gypi
diff --git a/base/base.gypi b/base/base.gypi
index 1d15b0a5bdfcd5e4fd4f8b6346158638ef52dd49..0c7fcd1cd33fa060fa000c6942c2d5c8ca566d7a 100644
--- a/base/base.gypi
+++ b/base/base.gypi
@@ -359,6 +359,12 @@
           'message_loop/message_pump_ozone.h',
           'message_loop/message_pump_win.cc',
           'message_loop/message_pump_win.h',
+          'metrics/chromeos_metrics.cc',
+          'metrics/chromeos_metrics.h',
+          'metrics/metric_sample.cc',
+          'metrics/metric_sample.h',
+          'metrics/crash_sample.cc',
+          'metrics/crash_sample.h',
           'metrics/sample_map.cc',
           'metrics/sample_map.h',
           'metrics/sample_vector.cc',
@@ -372,12 +378,18 @@
           'metrics/histogram_delta_serialization.cc',
           'metrics/histogram_delta_serialization.h',
           'metrics/histogram_flattener.h',
+          'metrics/histogram_sample.cc',
+          'metrics/histogram_sample.h',
           'metrics/histogram_samples.cc',
           'metrics/histogram_samples.h',
           'metrics/histogram_snapshot_manager.cc',
           'metrics/histogram_snapshot_manager.h',
+          'metrics/linearhistogram_sample.cc',
+          'metrics/linearhistogram_sample.h',
           'metrics/sparse_histogram.cc',
           'metrics/sparse_histogram.h',
+          'metrics/sparsehistogram_sample.cc',
+          'metrics/sparsehistogram_sample.h',
           'metrics/statistics_recorder.cc',
           'metrics/statistics_recorder.h',
           'metrics/stats_counters.cc',
@@ -387,6 +399,8 @@
           'metrics/user_metrics.cc',
           'metrics/user_metrics.h',
           'metrics/user_metrics_action.h',
+          'metrics/useraction_sample.cc',
+          'metrics/useraction_sample.cc',
           'move.h',
           'native_library.h',
           'native_library_mac.mm',