V8 Buildbot: Let leak checker use the v8-side wrapper.

scripts/slave/recipe_modules/v8/test_api.py

 # Copyright 2014 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.
 
 # Exposes the builder and recipe configurations to GenTests in recipes.
 
 import re
 
 from recipe_engine import recipe_test_api
 from . import builders
@@ skipping 407 matching lines @@
     return self.override_step_data(
         step_name, self.failures_example())
 
   def stdout(self, step_name, output, retcode=0):
     return self.override_step_data(
         step_name,
         self.m.raw_io.stream_output(output, stream='stdout'),
         retcode=retcode,
     )
 
-  def stderr(self, step_name, output, retcode=0):
-    return self.override_step_data(
-        step_name,
-        self.m.raw_io.stream_output(output, stream='stderr'),
-        retcode=retcode,
-    )
-
   @recipe_test_api.mod_test_data
   @staticmethod
   def test_failures(has_failures):
     return has_failures
 
   @recipe_test_api.mod_test_data
   @staticmethod
   def flakes(flakes):
     return flakes
 
   @recipe_test_api.mod_test_data
   @staticmethod
   def wrong_results(wrong_results):
     return wrong_results
 
   @recipe_test_api.mod_test_data
   @staticmethod
   def perf_failures(has_failures):
     return has_failures
 
   def __call__(self, test_failures=False, wrong_results=False,
                perf_failures=False, flakes=False):
     return (self.test_failures(test_failures) +
             self.wrong_results(wrong_results) +
             self.flakes(flakes) +
             self.perf_failures(perf_failures))