Issue 623854: Support unit annotations in ts_mon metrics

infra/services/sysmon/android_device_metrics.py

 # Copyright (c) 2016 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.
 
 import json
 import logging
 import os
 import re
 import socket
 import time
@@ skipping 22 matching lines @@
                                description='battery temperature in deg C')
 batt_charge = ts_mon.FloatMetric('dev/mobile/battery/charge',
                                  description='percentage charge of battery')
 dev_status = ts_mon.StringMetric('dev/mobile/status',
                                  description='operational state of device')
 dev_type = ts_mon.StringMetric('dev/mobile/type',
                                 description='device hardware or type')
 dev_os = ts_mon.StringMetric('dev/mobile/os',
                              description='operating system of the device')
 dev_uptime = ts_mon.FloatMetric('dev/mobile/uptime',
-                                description='device uptime in seconds')
+                                description='device uptime in seconds',
+                                units=ts_mon.MetricsDataUnits.SECONDS)
 mem_free = ts_mon.GaugeMetric(
     'dev/mobile/mem/free',
-    description='available memory (free + cached + buffers) in kb')
+    description='available memory (free + cached + buffers) in kb',
+    units=ts_mon.MetricsDataUnits.KIBIBYTES)
 mem_total = ts_mon.GaugeMetric(
     'dev/mobile/mem/total',
-    description='total memory (device ram - kernel leaks) in kb')
+    description='total memory (device ram - kernel leaks) in kb',
+    units=ts_mon.MetricsDataUnits.KIBIBYTES)
 proc_count = ts_mon.GaugeMetric('dev/mobile/proc/count',
                                 description='process count')
 
 metric_read_status = ts_mon.StringMetric(
     'dev/android_device_metric_read/status',
     description='status of the last metric read')
 
 
 def get_device_statuses(device_file=ANDROID_DEVICE_FILE, now=None):
   now = now or time.time()
@@ skipping 73 matching lines @@
   timestamp = json_data.get('timestamp', 0)
   if now >= timestamp + ANDROID_DEVICE_FILE_STALENESS_S:
     metric_read_status.set('stale_file')
     logging.error('Android device file %s is %ss stale (max %ss)',
                   device_file, now - timestamp,
                   ANDROID_DEVICE_FILE_STALENESS_S)
     return []
 
   metric_read_status.set('good')
   return json_data.get('devices', [])