Remove allocator_extension_thunks since this layer is not required

base/allocator/allocator.gyp

Index: base/allocator/allocator.gyp
diff --git a/base/allocator/allocator.gyp b/base/allocator/allocator.gyp
index ae93e9e03ca902fb8a10e66e1c2230f47a7d8ae7..97dbcc2838d11f5bcc923f6fade76807931f49e4 100644
--- a/base/allocator/allocator.gyp
+++ b/base/allocator/allocator.gyp
@@ -353,21 +353,6 @@
         }],
       ],
     },
-    {
-      # This library is linked in to src/base.gypi:base and allocator_unittests
-      # It can't depend on either and nothing else should depend on it - all
-      # other code should use the interfaced provided by base.
-      'target_name': 'allocator_extension_thunks',
-      'type': 'static_library',
-      'sources': [
-        'allocator_extension_thunks.cc',
-        'allocator_extension_thunks.h',
-      ],
-      'toolsets': ['host', 'target'],
-      'include_dirs': [
-        '../../'
-      ],
-    },
    ],
   'conditions': [
     ['OS=="win" and component!="shared_library"', {
@@ -399,7 +384,6 @@
           'type': 'executable',
           'dependencies': [
             'allocator',
-            'allocator_extension_thunks',
             '../../testing/gtest.gyp:gtest',
           ],
           'include_dirs': [
@@ -414,27 +398,6 @@
         },
       ],
     }],
-    ['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',
-            },
-          },
-        },
-      ],
-    }],
     ['use_allocator=="tcmalloc"', {
       'targets': [
          {