🚄 test_runner.py: Auto-detect output dir when running on bots

build/android/pylib/constants/__init__.py

 # Copyright (c) 2012 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.
 
 """Defines a set of constants shared by test runners and other scripts."""
 
 # TODO(jbudorick): Split these constants into coherent modules.
 
 # pylint: disable=W0212
 
 import collections
+import glob
 import logging
 import os
 import subprocess
 
 import devil.android.sdk.keyevent
 from devil.android.sdk import version_codes
 from devil.constants import exit_codes
 
 
 keyevent = devil.android.sdk.keyevent
@@ skipping 231 matching lines @@
   Raises:
     Exception: If no output directory is detected.
   """
   output_dir = os.environ.get('CHROMIUM_OUTPUT_DIR')
   out_dir = os.environ.get('CHROMIUM_OUT_DIR')
   if not output_dir and not out_dir:
     # If CWD is an output directory, then assume it's the desired one.
     if os.path.exists('build.ninja'):
       output_dir = os.getcwd()
       SetOutputDirectory(output_dir)
+    elif os.environ.get('CHROME_HEADLESS'):
+      # When running on bots, see if the output directory is obvious.
+      dirs = glob.glob(os.path.join(DIR_SOURCE_ROOT, 'out', '*', 'build.ninja'))

[jbudorick, 2016/03/14 17:41:35]

I don't think this will work with gyp bots, which will have both
out/Debug/build.ninja and out/Release/build.ninja.

+      if len(dirs) == 1:
+        SetOutputDirectory(dirs[0])
+      else:
+        raise Exception('Neither CHROMIUM_OUTPUT_DIR nor CHROMIUM_OUT_DIR '
+                        'has been set. CHROME_HEADLESS detected, but multiple '
+                        'out dirs exist: %r' % dirs)
     else:
       raise Exception('Neither CHROMIUM_OUTPUT_DIR nor CHROMIUM_OUT_DIR '
                       'has been set')
 
 
 # TODO(jbudorick): Convert existing callers to AdbWrapper.GetAdbPath() and
 # remove this.
 def GetAdbPath():
   from devil.android.sdk import adb_wrapper
   return adb_wrapper.AdbWrapper.GetAdbPath()
 
 
 # Exit codes
 ERROR_EXIT_CODE = exit_codes.ERROR
 INFRA_EXIT_CODE = exit_codes.INFRA
 WARNING_EXIT_CODE = exit_codes.WARNING