[test] Enable test status filtering by variant

tools/testrunner/objects/testcase.py

 # Copyright 2012 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
 #       copyright notice, this list of conditions and the following
 #       disclaimer in the documentation and/or other materials provided
@@ skipping 11 matching lines @@
 # LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 # DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 # THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 # (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 
 from . import output
 
 class TestCase(object):
-  def __init__(self, suite, path, variant='default', flags=None,
+  def __init__(self, suite, path, variant=None, flags=None,
                override_shell=None):
     self.suite = suite        # TestSuite object
     self.path = path          # string, e.g. 'div-mod', 'test-api/foo'
     self.flags = flags or []  # list of strings, flags specific to this test
     self.variant = variant    # name of the used testing variant
     self.override_shell = override_shell
     self.outcomes = set([])
     self.output = None
     self.id = None  # int, used to map result back to TestCase instance
     self.duration = None  # assigned during execution
@@ skipping 58 matching lines @@
     """
     return dict(self.__dict__, suite=self.suite.name)
 
   def __cmp__(self, other):
     # Make sure that test cases are sorted correctly if sorted without
     # key function. But using a key function is preferred for speed.
     return cmp(
         (self.suite.name, self.path, self.flags),
         (other.suite.name, other.path, other.flags),
     )
+
+  def __str__(self):
+    return "[%s/%s  %s]" % (self.suite.name, self.path, self.flags)