Add a snapshot of flutter/engine/src/build to our sdk

build/android/pylib/perf/surface_stats_collector_unittest.py

Index: build/android/pylib/perf/surface_stats_collector_unittest.py
diff --git a/build/android/pylib/perf/surface_stats_collector_unittest.py b/build/android/pylib/perf/surface_stats_collector_unittest.py
new file mode 100644
index 0000000000000000000000000000000000000000..e905d7314e33383f6c7e6e1fe3d81aa5e6be7d23
--- /dev/null
+++ b/build/android/pylib/perf/surface_stats_collector_unittest.py
@@ -0,0 +1,64 @@
+# Copyright 2013 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.
+
+"""Unittests for SurfaceStatsCollector."""
+# pylint: disable=W0212
+
+import unittest
+
+from pylib.perf.surface_stats_collector import SurfaceStatsCollector
+
+
+class TestSurfaceStatsCollector(unittest.TestCase):
+  @staticmethod
+  def _CreateUniformTimestamps(base, num, delta):
+    return [base + i * delta for i in range(1, num + 1)]
+
+  @staticmethod
+  def _CreateDictionaryFromResults(results):
+    dictionary = {}
+    for result in results:
+      dictionary[result.name] = result
+    return dictionary
+
+  def setUp(self):
+    self.refresh_period = 0.1
+
+  def testOneFrameDelta(self):
+    timestamps = self._CreateUniformTimestamps(0, 10, self.refresh_period)
+    results = self._CreateDictionaryFromResults(
+                  SurfaceStatsCollector._CalculateResults(
+                      self.refresh_period, timestamps, ''))
+
+    self.assertEquals(results['avg_surface_fps'].value,
+                      int(round(1 / self.refresh_period)))
+    self.assertEquals(results['jank_count'].value, 0)
+    self.assertEquals(results['max_frame_delay'].value, 1)
+    self.assertEquals(len(results['frame_lengths'].value), len(timestamps) - 1)
+
+  def testAllFramesTooShort(self):
+    timestamps = self._CreateUniformTimestamps(0, 10, self.refresh_period / 100)
+    self.assertRaises(Exception,
+                      SurfaceStatsCollector._CalculateResults,
+                      [self.refresh_period, timestamps, ''])
+
+  def testSomeFramesTooShort(self):
+    timestamps = self._CreateUniformTimestamps(0, 5, self.refresh_period)
+    # The following timestamps should be skipped.
+    timestamps += self._CreateUniformTimestamps(timestamps[4],
+                                                5,
+                                                self.refresh_period / 100)
+    timestamps += self._CreateUniformTimestamps(timestamps[4],
+                                                5,
+                                                self.refresh_period)
+
+    results = self._CreateDictionaryFromResults(
+                  SurfaceStatsCollector._CalculateResults(
+                      self.refresh_period, timestamps, ''))
+
+    self.assertEquals(len(results['frame_lengths'].value), 9)
+
+
+if __name__ == '__main__':
+  unittest.main()