Combine boolean MediaDeviceNotifications histograms to an enumerated histogram.

chrome/chrome_browser.gypi

 # 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.
 
 {
   'targets': [
     {
       'target_name': 'browser',
       'type': 'static_library',
@@ skipping 1903 matching lines @@
         'browser/system_monitor/media_device_notifications_utils.h',
         'browser/system_monitor/media_transfer_protocol_device_observer_chromeos.cc',
         'browser/system_monitor/media_transfer_protocol_device_observer_chromeos.h',
         'browser/system_monitor/removable_device_constants.cc',
         'browser/system_monitor/removable_device_constants.h',
         'browser/system_monitor/media_storage_util.cc',
         'browser/system_monitor/media_storage_util.h',
         'browser/system_monitor/media_storage_util_linux.cc',
         'browser/system_monitor/removable_device_notifications_chromeos.cc',
         'browser/system_monitor/removable_device_notifications_chromeos.h',
+        'browser/system_monitor/removable_device_notifications_histogram.cc',
+        'browser/system_monitor/removable_device_notifications_histogram.h',
         'browser/system_monitor/removable_device_notifications_linux.cc',
         'browser/system_monitor/removable_device_notifications_linux.h',
         'browser/system_monitor/removable_device_notifications_mac.h',
         'browser/system_monitor/removable_device_notifications_mac.mm',
         'browser/system_monitor/removable_device_notifications_window_win.cc',
         'browser/system_monitor/removable_device_notifications_window_win.h',
         'browser/tab_contents/background_contents.cc',
         'browser/tab_contents/background_contents.h',
         'browser/tab_contents/language_state.cc',
         'browser/tab_contents/language_state.h',
@@ skipping 890 matching lines @@
           'includes': [ '../build/jni_generator.gypi' ],
           'dependencies': [
             'android_jar_jni_headers',
           ],
         },
       ],
      },
     ],
   ],
 }