Update monet.

build/android/pylib/perf/test_runner.py

Index: build/android/pylib/perf/test_runner.py
diff --git a/build/android/pylib/perf/test_runner.py b/build/android/pylib/perf/test_runner.py
index 991fc003049152246d89d15f290b88c8c1b228c9..31eb0e9e9a4e4efa11cdcfe715d406c5a266fdb7 100644
--- a/build/android/pylib/perf/test_runner.py
+++ b/build/android/pylib/perf/test_runner.py
@@ -233,8 +233,15 @@ class TestRunner(base_test_runner.BaseTestRunner):
       return ''
 
     json_output_path = os.path.join(self._output_dir, 'results-chart.json')
-    with open(json_output_path) as f:
-      return f.read()
+    try:
+      with open(json_output_path) as f:
+        return f.read()
+    except IOError:
+      logging.exception('Exception when reading chartjson.')
+      logging.error('This usually means that telemetry did not run, so it could'
+                    ' not generate the file. Please check the device running'
+                    ' the test.')
+      return ''
 
   def _LaunchPerfTest(self, test_name):
     """Runs a perf test.
@@ -266,6 +273,10 @@ class TestRunner(base_test_runner.BaseTestRunner):
     logging.info(
         'temperature: %s (0.1 C)',
         str(self._device_battery.GetBatteryInfo().get('temperature')))
+    if self._options.max_battery_temp:
+      self._device_battery.LetBatteryCoolToTemperature(
+          self._options.max_battery_temp)
+
     logging.info('%s : %s', test_name, cmd)
     start_time = datetime.datetime.now()