Make the allocator_features gyp target target-only

base/allocator/allocator.gyp

 # Copyright (c) 2012 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.
 
 {
   'target_defaults': {
     'variables': {
       # This code gets run a lot and debugged rarely, so it should be fast
       # by default. See http://crbug.com/388949.
       'debug_optimize': '2',
@@ skipping 362 matching lines @@
           'target_conditions' : [
             ['_toolset=="target"', {
               'cflags!': [ '-finstrument-functions' ],
             }],
           ],
         }],
       ],  # conditions of 'allocator' target.
     },  # 'allocator' target.
     {
       # GN: //base/allocator:features
+      # When referenced from a target that might be compiled in the host
+      # toolchain, always refer to 'allocator_features#target'.
       'target_name': 'allocator_features',
       'includes': [ '../../build/buildflag_header.gypi' ],
-      'toolsets': ['host', 'target'],
       'variables': {
         'buildflag_header_path': 'base/allocator/features.h',
         'buildflag_flags': [
           'USE_EXPERIMENTAL_ALLOCATOR_SHIM=<(use_experimental_allocator_shim)',
         ],
       },
     },  # 'allocator_features' target.
   ],  # targets.
   'conditions': [
     ['OS=="win" and win_use_allocator_shim==1', {
@@ skipping 52 matching lines @@
               'sources': [
                 'allocator_shim_default_dispatch_to_glibc.cc',
               ],
             }],
           ]
         },  # 'unified_allocator_shim' target.
       ],
     }]
   ],
 }