Move sanitizer and symbol flags out of BUILDCONFIG

content/shell/BUILD.gn

 # Copyright 2014 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/features.gni")
+import("//build/config/sanitizers/sanitizers.gni")
 import("//build/config/ui.gni")
 import("//build/config/win/manifest.gni")
 import("//tools/grit/repack.gni")
 import("//tools/grit/grit_rule.gni")
 if (is_android) {
   import("//build/config/android/config.gni")
 }
 
 declare_args() {
   content_shell_product_name = "Content Shell"
@@ skipping 443 matching lines @@
     deps = [
       "//base",
       "//build/config/sanitizers:deps",
       "//components/crash/tools:crash_service",
     ]
 
     configs -= [ "//build/config/win:console" ]
     configs += [ "//build/config/win:windowed" ]
   }
 }