Improve readability of power monitoring code and add additional

tools/telemetry/telemetry/internal/platform/power_monitor/android_power_monitor_base.py

Index: tools/telemetry/telemetry/internal/platform/power_monitor/android_power_monitor_base.py
diff --git a/tools/telemetry/telemetry/internal/platform/power_monitor/android_power_monitor_base.py b/tools/telemetry/telemetry/internal/platform/power_monitor/android_power_monitor_base.py
new file mode 100644
index 0000000000000000000000000000000000000000..3bec7a3a5aa203874c08a26f851008885c83529b
--- /dev/null
+++ b/tools/telemetry/telemetry/internal/platform/power_monitor/android_power_monitor_base.py
@@ -0,0 +1,45 @@
+# Copyright 2014 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 logging
+
+from telemetry.internal.platform import power_monitor
+
+
+class AndroidPowerMonitorBase(power_monitor.PowerMonitor):
+
+  # Abstract class.
+  # pylint: disable=abstract-method
+
+  def _ParseVoltage(self, millivolts):
+    # Parse voltage information.
+    # If voltage is None, use 4.0 as default.
+    # Otherwise, convert millivolts to volts.
+    if millivolts is None:
+      # Converting at a nominal voltage of 4.0V, as those values are obtained by
+      # a heuristic, and 4.0V is the voltage we set when using a monsoon device.
+      voltage = 4.0
+      logging.warning('Unable to get device voltage. Using %s.', voltage)
+    else:
+      voltage = float(millivolts) / 1000
+      logging.info('Device voltage at %s', voltage)
+      return voltage
+
+  def _LogPowerAnomalies(self, power_data, package):
+    # Log anomalies in power data.
+    if power_data['energy_consumption_mwh'] == 0:
+      logging.warning('Power data is returning 0 for system total usage. %s'
+                      % (power_data))
+      if power_data['application_energy_consumption_mwh'] == 0:
+        logging.warning('Power data is returning 0 usage for %s. %s'
+                        % (package, power_data))
+
+  def _ChargingOff(self, battery):
+    battery.SetCharging(False)
+
+  def _ChargingOn(self, battery):
+    if battery.GetCharging():
+      logging.warning('Charging re-enabled during test.'
+                      'Results may be inaccurate.')
+      battery.SetCharging(True)