Make cygprofile order functions by process and thread ID.

tools/cygprofile/mergetraces_unittest.py

+# 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
+
+import mergetraces
+
+class GroupByProcessAndThreadIdTest(unittest.TestCase):
+  def runTest(self):
+    # (sec, usec, 'pid:tid', function address).
+    input_trace = [
+        (100, 10, '2000:2001', 0x5),
+        (100, 11, '2000:2001', 0x3),
+        (100, 11, '2000:2000', 0x1),
+        (100, 12, '2001:2001', 0x6),
+        (100, 13, '2000:2002', 0x8),
+        (100, 13, '2001:2002', 0x9),
+        (100, 14, '2000:2000', 0x7)
+    ]
+
+    # Functions should be grouped by thread-id and PIDs should not be
+    # interleaved.
+    expected_trace = [
+        (100, 10, '2000:2001', 0x5),
+        (100, 11, '2000:2001', 0x3),
+        (100, 11, '2000:2000', 0x1),
+        (100, 14, '2000:2000', 0x7),
+        (100, 13, '2000:2002', 0x8),
+        (100, 12, '2001:2001', 0x6),
+        (100, 13, '2001:2002', 0x9)
+    ]
+
+    grouped_trace = mergetraces.GroupByProcessAndThreadId(input_trace)
+
+    self.assertEqual(grouped_trace, expected_trace)