Add enable_reporting to fix size regression in Cronet.

tools/mb/mb_config.pyl

 # Copyright 2015 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.
 
 # This is a .pyl, or "Python Literal", file. You can treat it just like a
 # .json file, with the following exceptions:
 # * all keys must be quoted (use single quotes, please);
 # * comments are allowed, using '#' syntax; and
 # * trailing commas are allowed.
 
@@ skipping 1659 matching lines @@
       'gn_args': 'is_clang=true',
     },
 
     'no_clang': {
       'gn_args': 'is_clang=false',
     },
 
     'cronet': {
       'gn_args': ('disable_file_support=true disable_ftp_support=true '
                   'enable_websockets=false use_platform_icu_alternatives=true '
-                  'use_partition_alloc=false'),
+                  'use_partition_alloc=false enable_reporting=false'),
     },
 
     'cros_chrome_sdk': {
       # This is used so that the cros chrome_sdk (simplechrome) builders
       # can manage the list of GN args in their .ebuild
       # files and just pass through the desired arguments, hence not
       # really using MB. If a bot uses this mixin, we expect that
       # both GYP_DEFINES and GN_ARGS are set in the environment,
       # and that GYP_DEFINES has chromeos=1 and GN_ARGS has
       # target_os="chromeos" in it.
@@ skipping 282 matching lines @@
 
     'x64': {
       'gn_args': 'target_cpu="x64"',
     },
 
     'x86': {
       'gn_args': 'target_cpu="x86"',
     },
   },
 }