MB: Enable rtc_use_h264 for GYP builds for now.

webrtc/build/mb_config.pyl

 # Copyright (c) 2016 The WebRTC project authors. All Rights Reserved.
 #
 # Use of this source code is governed by a BSD-style license
 # that can be found in the LICENSE file in the root of the source
 # tree. An additional intellectual property rights grant can be found
 # in the file PATENTS.  All contributing project authors may
 # be found in the AUTHORS file in the root of the source tree.
 
 # FOR DETAILS ON THIS FILE SEE THE MAIN COPY IN //tools/mb/mb_config.pyl.
 # This is configuration for standalone WebRTC bots. It is used to keep the bot
@@ skipping 415 matching lines @@
     'goma': {
       # The MB code will properly escape goma_dir if necessary in the GYP
       # code path; the GN code path needs no escaping.
       'gn_args': 'use_goma=true',
       'gyp_defines': 'use_goma=1',
     },
 
     'gyp': {'type': 'gyp'},
 
     'gyp_limited_support_build': {
-      'gyp_defines': 'include_examples=0 include_tests=0 rtc_use_h264=0'
+      'gyp_defines': 'include_examples=0 include_tests=0'
     },
 
     'ios': {
       'gn_args': 'target_os="ios"',
       'gyp_defines': 'OS=ios',
     },
 
     'lsan': {
       'gn_args': 'is_lsan=true',
       'gyp_defines': 'lsan=1',
@@ skipping 85 matching lines @@
       'gn_args': 'target_cpu="x64"',
       'gyp_defines': 'target_arch=x64',
     },
 
     'x86': {
       'gn_args': 'target_cpu="x86"',
       'gyp_defines': 'target_arch=ia32',
     },
   },
 }