Revert of Remove old/unused atomicops code

base/allocator/BUILD.gn

 # Copyright (c) 2013 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.
 
 import("//build/config/allocator.gni")
 
 # Only executables and not libraries should depend on the allocator target;
 # only the application (the final executable) knows what allocator makes sense.
 # This "allocator" meta-target will forward to the default allocator according
 # to the build settings.
@@ skipping 45 matching lines @@
       # and checked in.
       "$tcmalloc_dir/src/config.h",
       "$tcmalloc_dir/src/config_android.h",
       "$tcmalloc_dir/src/config_linux.h",
       "$tcmalloc_dir/src/config_win.h",
 
       # tcmalloc native and forked files.
       "$tcmalloc_dir/src/base/abort.cc",
       "$tcmalloc_dir/src/base/abort.h",
       "$tcmalloc_dir/src/base/arm_instruction_set_select.h",
-      "$tcmalloc_dir/src/base/atomicops-internals-arm-generic.h",
-      "$tcmalloc_dir/src/base/atomicops-internals-arm-v6plus.h",
-      "$tcmalloc_dir/src/base/atomicops-internals-linuxppc.h",
-      "$tcmalloc_dir/src/base/atomicops-internals-macosx.h",
-      "$tcmalloc_dir/src/base/atomicops-internals-windows.h",
-      "$tcmalloc_dir/src/base/atomicops-internals-x86.cc",
-      "$tcmalloc_dir/src/base/atomicops-internals-x86.h",
-      "$tcmalloc_dir/src/base/atomicops.h",
-      "$tcmalloc_dir/src/base/basictypes.h",
-      "$tcmalloc_dir/src/base/commandlineflags.h",
-      "$tcmalloc_dir/src/base/cycleclock.h",
 
       # We don't list dynamic_annotations.c since its copy is already
       # present in the dynamic_annotations target.
       "$tcmalloc_dir/src/base/elf_mem_image.cc",
       "$tcmalloc_dir/src/base/elf_mem_image.h",
       "$tcmalloc_dir/src/base/linuxthreads.cc",
       "$tcmalloc_dir/src/base/linuxthreads.h",
       "$tcmalloc_dir/src/base/logging.cc",
       "$tcmalloc_dir/src/base/logging.h",
       "$tcmalloc_dir/src/base/low_level_alloc.cc",
@@ skipping 174 matching lines @@
   visibility = [ "//base/*" ]
   sources = [
     "allocator_extension_thunks.cc",
     "allocator_extension_thunks.h",
   ]
   if (is_android && !is_debug) {
     configs -= [ "//build/config/compiler:optimize" ]
     configs += [ "//build/config/compiler:optimize_max" ]
   }
 }