Remove added log handler in baseline_optimizer_unittest

Currently at HEAD when I run test-webkitpy I get a couple of
extraneous debug logs which contain:

Generating grammar tables from /usr/lib/python2.7/lib2to3/Grammar.txt
Generating grammar tables from /usr/lib/python2.7/lib2to3/PatternGrammar.txt

The purpose of this CL is to prevent test-webkitpy from
logging this to stderr.

Change-Id: Ica515a4f03f184cc1c3f91b6179de9317591c0bc
Reviewed-on: https://chromium-review.googlesource.com/807165Reviewed-by: Robert Ma <robertma@chromium.org>
Commit-Queue: Quinten Yearsley <qyearsley@chromium.org>
Cr-Commit-Position: refs/heads/master@{#521487}

third_party/WebKit/Tools/Scripts/webkitpy/common/checkout/baseline_optimizer_unittest.py

@@ -27,7 +27,6 @@
 # OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 import unittest
-import logging
 import sys
 
 from webkitpy.common.checkout.baseline_optimizer import BaselineOptimizer
@@ -36,11 +35,6 @@ from webkitpy.common.system.filesystem_mock import MockFileSystem
 from webkitpy.common.path_finder import PathFinder
 from webkitpy.layout_tests.builder_list import BuilderList
 
-# Print out useful debug logs in very verbose (-vv) mode.
-_log = logging.getLogger()
-_log.level = logging.DEBUG
-_log.addHandler(logging.StreamHandler(sys.stderr))
-
 ALL_PASS_TESTHARNESS_RESULT = """This is a testharness.js-based test.
 PASS woohoo
 Harness: the test ran to completion.