Explictly pass -marm when arm mode is required

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/buildflag_header.gni")
 import("//build/config/allocator.gni")
 import("//build/config/compiler/compiler.gni")
 
 declare_args() {
   # Provide a way to force disable debugallocation in Debug builds,
@@ skipping 198 matching lines @@
 
     # Disable the heap checker in tcmalloc.
     defines = [ "NO_HEAP_CHECK" ]
 
     include_dirs = [
       ".",
       "$tcmalloc_dir/src/base",
       "$tcmalloc_dir/src",
     ]
 
-    configs -= [
-      "//build/config/compiler:chromium_code",
-
-      # Thumb mode disabled due to bug in clang integrated assembler
-      # TODO(https://llvm.org/bugs/show_bug.cgi?id=31058)
-      "//build/config/compiler:compiler_arm_thumb",
-    ]
+    configs -= [ "//build/config/compiler:chromium_code" ]
     configs += [
       "//build/config/compiler:no_chromium_code",
       ":tcmalloc_flags",
     ]
 
+    # Thumb mode disabled due to bug in clang integrated assembler
+    # TODO(https://llvm.org/bugs/show_bug.cgi?id=31058)
+    configs -= [ "//build/config/compiler:compiler_arm_thumb" ]
+    configs += [ "//build/config/compiler:compiler_arm" ]
+
     # TODO(crbug.com/633719) Make tcmalloc work with AFDO if possible.
     configs -= [ "//build/config/compiler:afdo" ]
 
     deps = []
 
     if (enable_profiling) {
       sources += [
         "$tcmalloc_dir/src/base/thread_lister.c",
         "$tcmalloc_dir/src/base/thread_lister.h",
         "$tcmalloc_dir/src/profile-handler.cc",
@@ skipping 100 matching lines @@
       sources += [ "allocator_shim_default_dispatch_to_glibc.cc" ]
     } else if (is_android && use_allocator == "none") {
       sources += [
         "allocator_shim_default_dispatch_to_linker_wrapped_symbols.cc",
         "allocator_shim_override_linker_wrapped_symbols.h",
       ]
       all_dependent_configs = [ ":wrap_malloc_symbols" ]
     }
   }
 }