Revert of [ObjC ARC] Converts ios/public/consumer/base:base to ARC.Automatically generated ARCMigrat

ios/public/consumer/base/BUILD.gn

 # Copyright 2016 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.
 
 source_set("base") {
-  configs += [ "//build/config/compiler:enable_arc" ]
   sources = [
-    "//ios/consumer/base/debugger.cc",
+    "//ios/consumer/base/debugger.mm",
     "//ios/public/consumer/base/debugger.h",
   ]
   deps = [
     "//base",
   ]
 }