Remove allocator_extension_thunks since this layer is not required

base/base.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.
 
 {
   'variables': {
     'chromium_code': 1,
   },
   'includes': [
     '../build/win_precompile.gypi',
     'base.gypi',
   ],
   'targets': [
     {
       'target_name': 'base',
       'type': '<(component)',
       'toolsets': ['host', 'target'],
       'variables': {
         'base_target': 1,
         'enable_wexit_time_destructors': 1,
         'optimize': 'max',
       },
       'dependencies': [
         'base_debugging_flags',
         'base_static',
-        'allocator/allocator.gyp:allocator_extension_thunks',
         '../testing/gtest.gyp:gtest_prod',
         '../third_party/modp_b64/modp_b64.gyp:modp_b64',
         'third_party/dynamic_annotations/dynamic_annotations.gyp:dynamic_annotations',
       ],
       # TODO(gregoryd): direct_dependent_settings should be shared with the
       #  64-bit target, but it doesn't work due to a bug in gyp
       'direct_dependent_settings': {
         'include_dirs': [
           '..',
         ],
@@ skipping 1103 matching lines @@
         # (the normal build is 32 bits).
         {
           'target_name': 'base_win64',
           'type': '<(component)',
           'variables': {
             'base_target': 1,
           },
           'dependencies': [
             'base_debugging_flags',
             'base_static_win64',
-            'allocator/allocator.gyp:allocator_extension_thunks_win64',
             '../third_party/modp_b64/modp_b64.gyp:modp_b64_win64',
             'third_party/dynamic_annotations/dynamic_annotations.gyp:dynamic_annotations_win64',
             'trace_event/etw_manifest/etw_manifest.gyp:etw_manifest',
           ],
           # TODO(gregoryd): direct_dependent_settings should be shared with the
           # 32-bit target, but it doesn't work due to a bug in gyp
           'direct_dependent_settings': {
             'include_dirs': [
               '..',
             ],
@@ skipping 569 matching lines @@
             '../build/isolate.gypi',
           ],
           'sources': [
             'base_unittests.isolate',
           ],
         },
       ],
     }],
   ],
 }