Android perf: force flushing stdout.

build/android/pylib/perf/test_runner.py

 # 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.
 
 """Runs perf tests.
 
 Our buildbot infrastructure requires each slave to run steps serially.
 This is sub-optimal for android, where these steps can run independently on
 multiple connected devices.
 
@@ skipping 88 matching lines @@
       self._stopped.wait(_HeartBeatLogger._PRINT_INTERVAL)
 
   def write(self, data):
     self._len += len(data)
 
   def flush(self):
     now = time.time()
     if now - self._tick >= _HeartBeatLogger._PRINT_INTERVAL:
       self._tick = now
       print '--single-step output length %d' % self._len
+      sys.stdout.flush()
 
   def stop(self):
     self._stopped.set()
 
 
 class TestRunner(base_test_runner.BaseTestRunner):
   def __init__(self, test_options, device, tests, flaky_tests):
     """A TestRunner instance runs a perf test on a single device.
 
     Args:
@@ skipping 109 matching lines @@
     Returns:
       A tuple of (TestRunResults, retry).
     """
     output, result_type = self._LaunchPerfTest(test_name)
     results = base_test_result.TestRunResults()
     results.AddResult(base_test_result.BaseTestResult(test_name, result_type))
     retry = None
     if not results.DidRunPass():
       retry = test_name
     return results, retry