Turn down verbosity in trace_test.

The logs are huge when these tests fail, and for no good reason as far
as I can tell. The huge amount of logging might actually be slowing
down the tests.

BUG=638744
CQ_INCLUDE_TRYBOTS=master.tryserver.chromium.linux:linux_optional_gpu_tests_rel;master.tryserver.chromium.mac:mac_optional_gpu_tests_rel;master.tryserver.chromium.win:win_optional_gpu_tests_rel;master.tryserver.chromium.android:android_optional_gpu_tests_rel
TBR=zmo@chromium.org

Review-Url: https://codereview.chromium.org/2343063005
Cr-Commit-Position: refs/heads/master@{#419381}

content/test/gpu/gpu_tests/trace_test.py

@@ -111,9 +111,6 @@ class TraceTest(TraceTestBase):
   def _CreateExpectations(self):
     return trace_test_expectations.TraceTestExpectations()
 
-  def CustomizeBrowserOptions(self, options):
-    options.logging_verbosity = options.VERBOSE_LOGGING
-
 
 class DeviceTraceTest(TraceTestBase):
   """Tests GPU Device traces show up on devices that support it."""