Merge up to bleeding_edge r7201 to isolates branch.

tools/test.py

 #!/usr/bin/env python
 #
 # Copyright 2008 the V8 project authors. All rights reserved.
 # Redistribution and use in source and binary forms, with or without
 # modification, are permitted provided that the following conditions are
 # met:
 #
 #     * Redistributions of source code must retain the above copyright
 #       notice, this list of conditions and the following disclaimer.
 #     * Redistributions in binary form must reproduce the above
@@ skipping 356 matching lines @@
                       full_command,
                       output,
                       self.context.store_unexpected_output)
 
   def BeforeRun(self):
     pass
 
   def AfterRun(self, result):
     pass
 
+  def GetCustomFlags(self, mode):
+    return None
+
   def Run(self):
     self.BeforeRun()
     try:
       result = self.RunCommand(self.GetCommand())
     finally:
       self.AfterRun(result)
     return result
 
   def Cleanup(self):
     return
@@ skipping 288 matching lines @@
   def GetVm(self, mode):
     name = self.vm_root + SUFFIX[mode]
     if utils.IsWindows() and not name.endswith('.exe'):
       name = name + '.exe'
     return name
 
   def GetVmCommand(self, testcase, mode):
     return [self.GetVm(mode)] + self.GetVmFlags(testcase, mode)
 
   def GetVmFlags(self, testcase, mode):
-    return testcase.variant_flags + FLAGS[mode]
+    flags = testcase.GetCustomFlags(mode)
+    if flags is None:
+      flags = FLAGS[mode]
+    return testcase.variant_flags + flags
 
   def GetTimeout(self, testcase, mode):
     result = self.timeout * TIMEOUT_SCALEFACTOR[mode]
     if '--stress-opt' in self.GetVmFlags(testcase, mode):
       return result * 2
     else:
       return result
 
 def RunTestCases(cases_to_run, progress, tasks):
   progress = PROGRESS_INDICATORS[progress](cases_to_run)
@@ skipping 779 matching lines @@
     for entry in timed_tests[:20]:
       t = FormatTime(entry.duration)
       sys.stderr.write("%4i (%s) %s\n" % (index, t, entry.GetLabel()))
       index += 1
 
   return result
 
 
 if __name__ == '__main__':
   sys.exit(Main())