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

tools/telemetry/telemetry/core/platform/timeline_objects_unittest.py

Index: tools/telemetry/telemetry/core/platform/timeline_objects_unittest.py
diff --git a/tools/telemetry/telemetry/core/platform/timeline_objects_unittest.py b/tools/telemetry/telemetry/core/platform/timeline_objects_unittest.py
new file mode 100644
index 0000000000000000000000000000000000000000..19029a4add159569bc03a3113844ea7001e7347c
--- /dev/null
+++ b/tools/telemetry/telemetry/core/platform/timeline_objects_unittest.py
@@ -0,0 +1,48 @@
+# 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 json
+import unittest
+import StringIO
+
+from telemetry.core.platform import timeline_objects
+
+
+class PlatformTimeLineObjectTest(unittest.TestCase):
+
+  def testIdleWakeupCountMath(self):
+    pid1 = 1
+    pid2 = 2
+
+    a = timeline_objects.IdleStatsData(pid1, 5)
+    b = timeline_objects.IdleStatsData(pid2, 1)
+    c = timeline_objects.IdleStatsData(pid1, 1)
+
+    # Test addition.
+    addition_result = (a + b).idle_wakeup_count_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).idle_wakeup_count_by_pid
+    self.assertEquals(4, subtraction_result[pid1])
+    self.assertEquals(1, len(subtraction_result.keys()))
+
+    self.assertEquals(6, (a + b).IdleWakeupCount())
+
+  def testIdleWakeupCountReporting(self):
+    pid1 = 1
+    pid2 = 2
+
+    a = timeline_objects.IdleStatsData(pid1, 1)
+    b = timeline_objects.IdleStatsData(pid2, 99)
+    c = a + b
+    self.assertEquals(100, c.IdleWakeupCount())
+
+    # Test serialization.
+    output = StringIO.StringIO()
+    c.Serialize(output)
+    deserialized = json.loads(output.getvalue())
+    self.assertEquals(100, deserialized['idleWakeupCount'])