Revert of Improve readability of power monitoring code and add additional

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

Index: tools/telemetry/telemetry/internal/platform/power_monitor/android_temperature_monitor.py
diff --git a/tools/telemetry/telemetry/internal/platform/power_monitor/android_temperature_monitor.py b/tools/telemetry/telemetry/internal/platform/power_monitor/android_temperature_monitor.py
index ebf5774eb44e1fe8b96d5c2eb7e8654d6a631288..436dac47cf27f8a642aaf7238cd5796303808257 100644
--- a/tools/telemetry/telemetry/internal/platform/power_monitor/android_temperature_monitor.py
+++ b/tools/telemetry/telemetry/internal/platform/power_monitor/android_temperature_monitor.py
@@ -1,8 +1,6 @@
 # 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
 
@@ -27,26 +25,35 @@
     return self._GetBoardTemperatureCelsius() is not None
 
   def StartMonitoringPower(self, browser):
-    # don't call _CheckStart() because this is temperature, not power
-    # therefore, StartMonitoringPower and StopMonitoringPower
-    # do not need to be paired
     pass
 
   def StopMonitoringPower(self):
-    avg_temp = self._GetBoardTemperatureCelsius()
-    if avg_temp is None:
-      return {'identifier': 'android_temperature_monitor'}
-    else:
-      return {'identifier': 'android_temperature_monitor',
-              'platform_info': {'average_temperature_c': avg_temp}}
+    power_data = {'identifier': 'android_temperature_monitor'}
+
+    # Take the current temperature as average based on the assumption that the
+    # temperature changes slowly during measurement time.
+    average_temperature = self._GetBoardTemperatureCelsius()
+    if average_temperature is None:
+      return power_data
+
+    # Insert temperature into the appropriate position in the dictionary
+    # returned by StopMonitoringPower() creating appropriate sub-dictionaries on
+    # the way if necessary.
+    temperature_path = [
+        'platform_info', 'average_temperature_c']
+    temperature_insertion_point = power_data
+    for path_element in temperature_path[:-1]:
+      if not path_element in temperature_insertion_point:
+        temperature_insertion_point[path_element] = {}
+      temperature_insertion_point = temperature_insertion_point[path_element]
+    assert temperature_path[-1] not in temperature_insertion_point
+    temperature_insertion_point[temperature_path[-1]] = average_temperature
+
+    return power_data
 
   def _GetBoardTemperatureCelsius(self):
     try:
       contents = self._device.ReadFile(_TEMPERATURE_FILE)
       return float(contents) if contents else None
-    except ValueError:
-      logging.warning('String returned from device.ReadFile(_TEMPERATURE_FILE) '
-                      'in invalid format.')
-      return None
     except device_errors.CommandFailedError:
       return None