Add dvlog_always_on to enable DVLOG without DEBUG and DCHECK option

build/config/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")
 import("//build/config/c++/c++.gni")
 import("//build/config/chrome_build.gni")
 import("//build/config/chromecast_build.gni")
 import("//build/config/crypto.gni")
 import("//build/config/dcheck_always_on.gni")
+import("//build/config/dvlog_always_on.gni")
 import("//build/config/features.gni")
 import("//build/config/pch.gni")
 import("//build/config/sanitizers/sanitizers.gni")
 import("//build/config/ui.gni")
 import("//build/toolchain/goma.gni")
 
 declare_args() {
   # When set (the default) enables C++ iterator debugging in debug builds.
   # Iterator debugging is always off in release builds (technically, this flag
   # affects the "debug" config, which is always available but applied by
@@ skipping 26 matching lines @@
 # This will also allow you to scope your build flag to a BUILD.gn file (or a
 # .gni file if you need it from more than one place) rather than making global
 # flags. See //build/config/BUILDCONFIG.gn for advice on where to define
 # build flags.
 config("feature_flags") {
   # Don't use deprecated V8 APIs anywhere.
   defines = [ "V8_DEPRECATION_WARNINGS" ]
   if (dcheck_always_on) {
     defines += [ "DCHECK_ALWAYS_ON=1" ]
   }
+  if (dvlog_always_on) {
+    defines += [ "DVLOG_ALWAYS_ON=1" ]
+  }
   if (use_udev) {
     # TODO(brettw) should probably be "=1".
     defines += [ "USE_UDEV" ]
   }
   if (use_ash) {
     defines += [ "USE_ASH=1" ]
   }
   if (use_aura) {
     defines += [ "USE_AURA=1" ]
   }
@@ skipping 309 matching lines @@
       # variant for each language used in the target).
       precompiled_source = "//build/precompile.cc"
 
       # Force include the header.
       cflags = [ "/FI$precompiled_header" ]
     } else if (is_mac) {
       precompiled_source = "//build/precompile.h"
     }
   }
 }