clovis: Enable the disable-by-default-blink.debug.layout tracing category.

tools/android/loading/tracing.py

 # Copyright 2016 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.
 
 """Monitor tracing events on chrome via chrome remote debugging."""
 
 import bisect
 import itertools
 import logging
 import operator
 
 import devtools_monitor
 
 
 _DISABLED_CATEGORIES = ('cc',) # Contains a lot of events, none of which we use.
 INITIAL_CATEGORIES = (
-    'toplevel', 'blink', 'v8', 'java', 'devtools.timeline',
-    'blink.user_timing', 'blink.net') + tuple(
-        '-' + cat for cat in _DISABLED_CATEGORIES)
+    ('toplevel', 'blink', 'v8', 'java', 'devtools.timeline',
+     'blink.user_timing', 'blink.net', 'disabled-by-default-blink.debug.layout')
+    + tuple('-' + cat for cat in _DISABLED_CATEGORIES))
 
 
 class TracingTrack(devtools_monitor.Track):
   """Grabs and processes trace event messages.
 
   See https://goo.gl/Qabkqk for details on the protocol.
   """
   def __init__(self, connection, additional_categories=None,
                fetch_stream=False):
     """Initialize this TracingTrack.
@@ skipping 519 matching lines @@
     self._left = _IntervalTree(self.start, left_end, left_events)
     self._right = _IntervalTree(right_start, self.end, right_events)
 
   def _IsLeaf(self):
     return self._left is None
 
   @classmethod
   def _Overlaps(cls, event, start, end):
     return (min(end, event.end_msec) - max(start, event.start_msec) > 0
             or start <= event.start_msec < end)  # For instant events.