Refactor of Histogram related code

base/base.gyp

 # Copyright (c) 2012 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 {
   'variables': {
     'chromium_code': 1,
   },
   'includes': [
     '../build/win_precompile.gypi',
@@ skipping 419 matching lines @@
         'memory/weak_ptr_unittest.nc',
         'message_loop_proxy_impl_unittest.cc',
         'message_loop_proxy_unittest.cc',
         'message_loop_unittest.cc',
         'message_pump_glib_unittest.cc',
         'message_pump_libevent_unittest.cc',
         'metrics/bucket_ranges_unittest.cc',
         'metrics/field_trial_unittest.cc',
         'metrics/histogram_unittest.cc',
         'metrics/stats_table_unittest.cc',
+        'metrics/statistics_recorder_unittest.cc',
         'observer_list_unittest.cc',
         'os_compat_android_unittest.cc',
         'path_service_unittest.cc',
         'pickle_unittest.cc',
         'platform_file_unittest.cc',
         'pr_time_unittest.cc',
         'process_util_unittest.cc',
         'process_util_unittest_ios.cc',
         'process_util_unittest_mac.h',
         'process_util_unittest_mac.mm',
@@ skipping 547 matching lines @@
             'test_suite_name': 'base_unittests',
             'input_shlib_path': '<(SHARED_LIB_DIR)/<(SHARED_LIB_PREFIX)base_unittests<(SHARED_LIB_SUFFIX)',
             'input_jars_paths': ['<(PRODUCT_DIR)/lib.java/chromium_base.jar',],
           },
           'includes': [ '../build/apk_test.gypi' ],
         },
       ],
     }],
   ],
 }