[Telemetry] Fix idle wakeup reporting in the face of dead processes

tools/telemetry/telemetry/core/platform/process_statistic_timeline_data_unittest.py

Index: tools/telemetry/telemetry/core/platform/process_statistic_timeline_data_unittest.py
diff --git a/tools/telemetry/telemetry/core/platform/process_statistic_timeline_data_unittest.py b/tools/telemetry/telemetry/core/platform/process_statistic_timeline_data_unittest.py
new file mode 100644
index 0000000000000000000000000000000000000000..be50bd610fd02032c1271416922ea38e4e862dcd
--- /dev/null
+++ b/tools/telemetry/telemetry/core/platform/process_statistic_timeline_data_unittest.py
@@ -0,0 +1,47 @@
+# 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 unittest
+
+from telemetry.core.platform import process_statistic_timeline_data
+
+
+class ProcessStatisticTimelineDataTest(unittest.TestCase):
+
+  def testProcessStatisticValueMath(self):
+    pid1 = 1
+    pid2 = 2
+
+    a = process_statistic_timeline_data.ProcessStatisticTimelineData(pid1, 5)
+    b = process_statistic_timeline_data.ProcessStatisticTimelineData(pid2, 1)
+    c = process_statistic_timeline_data.ProcessStatisticTimelineData(pid1, 1)
+
+    # Test addition.
+    addition_result = (a + b).value_by_pid
+    self.assertEquals(5, addition_result[pid1])
+    self.assertEquals(1, addition_result[pid2])
+    self.assertEquals(2, len(addition_result.keys()))
+
+    # Test subtraction.
+    subtraction_result = ((a + b) - c).value_by_pid
+    self.assertEquals(4, subtraction_result[pid1])
+    self.assertEquals(1, subtraction_result[pid2])
+    self.assertEquals(2, len(subtraction_result.keys()))
+
+    # Test subtraction with a pid that exists only in rhs.
+    subtraction_results1 = (a - (b + c)).value_by_pid
+    self.assertEquals(4, subtraction_results1[pid1])
+    self.assertEquals(1, len(subtraction_results1.keys()))
+
+    # Test calculation of total sum.
+    self.assertEquals(6, (a + b).total_sum())
+
+  def testProcessStatisticValueSummary(self):
+    pid1 = 1
+    pid2 = 2
+
+    a = process_statistic_timeline_data.ProcessStatisticTimelineData(pid1, 1)
+    b = process_statistic_timeline_data.ProcessStatisticTimelineData(pid2, 99)
+    c = a + b
+    self.assertEquals(100, c.total_sum())