Remove allocator_extension_thunks since this layer is not required

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 340 matching lines @@
         }],
         ['order_profiling != 0', {
           'target_conditions' : [
             ['_toolset=="target"', {
               'cflags!': [ '-finstrument-functions' ],
             }],
           ],
         }],
       ],  # conditions of 'allocator' target.
     },  # 'allocator' target.
-    {
-      'target_name': 'allocator_extension_thunks',
-      'type': 'static_library',
-      'sources': [
-        'allocator_extension_thunks.cc',
-        'allocator_extension_thunks.h',
-      ],
-      'toolsets': ['host', 'target'],
-      'include_dirs': [
-        '../../'
-      ],
-    },
-   ],
+  ],  # targets.
   'conditions': [
     ['OS=="win" and component!="shared_library"', {
       'targets': [
         {
           'target_name': 'libcmt',
           'type': 'none',
           'actions': [
             {
               'action_name': 'libcmt',
               'inputs': [
                 'prep_libc.py',
               ],
               'outputs': [
                 '<(SHARED_INTERMEDIATE_DIR)/allocator/libcmt.lib',
               ],
               'action': [
                 'python',
                 'prep_libc.py',
                 '$(VCInstallDir)lib',
                 '<(SHARED_INTERMEDIATE_DIR)/allocator',
                 '<(target_arch)',
               ],
             },
           ],
         },
       ],
     }],
-    ['OS=="win" and target_arch=="ia32"', {
-      'targets': [
-        {
-          'target_name': 'allocator_extension_thunks_win64',
-          'type': 'static_library',
-          'sources': [
-            'allocator_extension_thunks.cc',
-            'allocator_extension_thunks.h',
-          ],
-          'toolsets': ['host', 'target'],
-          'include_dirs': [
-            '../../'
-          ],
-          'configurations': {
-            'Common_Base': {
-              'msvs_target_platform': 'x64',
-            },
-          },
-        },
-      ],
-    }],
   ],
 }