make test.py more reselient to flakyness in xvfb-run + DumpRenderTree

tools/testing/architecture.py

 # Copyright (c) 2011, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 #
 
 import os
 import platform
 import re
 import shutil
 import subprocess
@@ skipping 101 matching lines @@
 DART_OPTIONS_PATTERN = re.compile(r'// DartOptions=(.*)')
 
 # Pattern for checking if the test is a web test.
 DOM_IMPORT_PATTERN = re.compile(r'#import.*(dart:(dom|html)|html\.dart).*\);',
                                 re.MULTILINE)
 
 # Pattern for matching the output of a browser test.
 BROWSER_OUTPUT_PASS_PATTERN = re.compile(r'^Content-Type: text/plain\nPASS$',
                                          re.MULTILINE)
 
+# Pattern for matching flaky errors of browser tests. xvfb-run by default uses
+# DISPLAY=:99, we keep that in the error pattern to avoid matching real
+# errors when DISPLAY is set incorrectly.
+BROWSER_FLAKY_DISPLAY_ERR_PATTERN = re.compile(
+    r'Gtk-WARNING \*\*: cannot open display: :99', re.MULTILINE)
+
 # Pattern for checking if the test is a library in itself.
 LIBRARY_DEFINITION_PATTERN = re.compile(r'^#library\(.*\);',
                                         re.MULTILINE)
 SOURCE_OR_IMPORT_PATTERN = re.compile(r'^#(source|import)\(.*\);',
                                       re.MULTILINE)
 
 
 class Error(Exception):
   """Base class for exceptions in this module."""
   pass
@@ skipping 152 matching lines @@
     f.close()
 
     drt_flags.append(html_output_file)
 
     return [drt_location] + drt_flags
 
   def HasFailed(self, output):
     """Return True if the 'PASS' result string isn't in the output."""
     return not BROWSER_OUTPUT_PASS_PATTERN.search(output)
 
+  def WasFlakyDrt(self, error):
+    """Return whether the error indicates a flaky error from running.
+       DumpRenderTree within xvfb-run.
+    """
+    return BROWSER_FLAKY_DISPLAY_ERR_PATTERN.search(error)
+
   def RunTest(self, verbose):
     """Calls GetRunCommand() and executes the returned commandline.
 
     Args:
       verbose: if True, print additional diagnostics to stdout.
 
     Returns:
       Return code from executable. 0 == PASS, 253 = CRASH, anything
       else is treated as FAIL
     """
@@ skipping 259 matching lines @@
     return WebDriverArchitecture(root_path, arch, mode, component, test)
 
   elif component in ['vm', 'frog', 'frogsh']:
     return StandaloneArchitecture(root_path, arch, mode, component, test)
 
   elif component == 'leg':
     return LegArchitecture(root_path, arch, mode, component, test)
 
   elif component == 'dartc':
     return DartcArchitecture(root_path, arch, mode, component, test)