Move spin_lock into partition_allocator.

base/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.
 
 # HOW TO WRITE CONDITIONALS IN THIS FILE
 # ======================================
 #
 # In many other places, one would write a conditional that expresses all the
 # cases when a source file is used or unused, and then either add or subtract
 # it from the sources list in that case
@@ skipping 1293 matching lines @@
       # Add stuff that doesn't work in NaCl.
       sources += [
         # PartitionAlloc uses SpinLock, which doesn't work in NaCl (see below).
         "allocator/partition_allocator/address_space_randomization.cc",
         "allocator/partition_allocator/address_space_randomization.h",
         "allocator/partition_allocator/oom.h",
         "allocator/partition_allocator/page_allocator.cc",
         "allocator/partition_allocator/page_allocator.h",
         "allocator/partition_allocator/partition_alloc.cc",
         "allocator/partition_allocator/partition_alloc.h",
+        "allocator/partition_allocator/spin_lock.cc",
+        "allocator/partition_allocator/spin_lock.h",
       ]
     }
   }
 
-  # SpinLock uses inline assembly that doesn't work on NaCl, and for which there
-  # is no code for ARMv6.
-  if (!is_nacl && (current_cpu != "arm" || arm_version >= 7)) {
-    sources += [
-      "synchronization/spin_lock.cc",
-      "synchronization/spin_lock.h",
-    ]
-  }
-
   # Windows.
   if (is_win) {
     sources += [
       "power_monitor/power_monitor_device_source_win.cc",
       "profiler/win32_stack_frame_unwinder.cc",
       "profiler/win32_stack_frame_unwinder.h",
     ]
 
     sources -= [
       "file_descriptor_store.cc",
@@ skipping 1315 matching lines @@
 }
 
 fuzzer_test("base_json_correctness_fuzzer") {
   sources = [
     "json/correctness_fuzzer.cc",
   ]
   deps = [
     ":base",
   ]
 }