adb_profile_chrome: Add perf profiler

build/android/chrome_profiler/trace_packager_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.
+
+from chrome_profiler import trace_packager
+
+import json
+import tempfile
+import unittest
+
+
+class TracePackagerTest(unittest.TestCase):
+  def testJsonTraceMerging(self):
+    t1 = {'traceEvents': [{'ts': 123, 'ph': 'b'}]}
+    t2 = {'traceEvents': [], 'stackFrames': ['blah']}
+
+    # Both trace files will be merged to a third file and will get deleted in
+    # the process, so there's no need for NamedTemporaryFile to do the
+    # deletion.
+    with tempfile.NamedTemporaryFile(delete=False) as f1, \
+        tempfile.NamedTemporaryFile(delete=False) as f2:
+      f1.write(json.dumps(t1))
+      f2.write(json.dumps(t2))
+      f1.flush()
+      f2.flush()
+
+      with tempfile.NamedTemporaryFile() as output:
+        trace_packager.PackageTraces([f1.name, f2.name],
+                                     output.name,
+                                     compress=False,
+                                     write_json=True)
+        with open(output.name) as output:
+          output = json.load(output)
+          self.assertEquals(output['traceEvents'], t1['traceEvents'])
+          self.assertEquals(output['stackFrames'], t2['stackFrames'])