Audit GN cflags and defines to match GYP build.

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/crypto.gni")
 import("//build/config/features.gni")
 import("//build/config/ui.gni")
 import("//build/module_args/v8.gni")
 
 declare_args() {
   # When set, turns off the (normally-on) iterator debugging and related stuff
   # that is normally turned on for Debug builds. These are generally useful for
   # catching bugs but in some cases may cause conflicts or excessive slowness.
   disable_iterator_debugging = false
 
-  # Set to true to not store any build metadata (this isn't working yet but
-  # this flag will help us to get there). See http://crbug.com/314403.
-  # TODO(sebmarchand): Update this comment once this flag guarantee that
-  #     there's no build metadata in the build artifacts.
-  dont_embed_build_metadata = false
+  # Set to true to not store any build metadata, e.g. ifdef out all __DATE__
+  # and __TIME__. Set to 0 to reenable the use of these macros in the code
+  # base. See http://crbug.com/314403.
+  #
+  # Continue to embed build meta data in Official builds, basically the
+  # time it was built.
+  # TODO(maruel): This decision should be revisited because having an
+  # official deterministic build has high value too but MSVC toolset can't
+  # generate anything deterministic with WPO enabled AFAIK.
+  dont_embed_build_metadata = is_official_build
 
   # Set to true to enable dcheck in Release builds.
   dcheck_always_on = false
 }
 
 # TODO(brettw) Most of these should be removed. Instead of global feature
 # flags, we should have more modular flags that apply only to a target and its
 # dependents. For example, depending on the "x11" meta-target should define
 # USE_X11 for all dependents so that everything that could use X11 gets the
 # define, but anything that doesn't depend on X11 doesn't see it.
@@ skipping 175 matching lines @@
   }
   if (proprietary_codecs) {
     defines += [ "USE_PROPRIETARY_CODECS" ]
   }
   if (enable_hangout_services_extension) {
     defines += [ "ENABLE_HANGOUT_SERVICES_EXTENSION=1" ]
   }
   if (v8_use_external_startup_data) {
     defines += [ "V8_USE_EXTERNAL_STARTUP_DATA" ]
   }
+  if (enable_background) {
+    defines += [ "ENABLE_BACKGROUND=1" ]
+  }
+  if (enable_pre_sync_backup) {
+    defines += [ "ENABLE_PRE_SYNC_BACKUP" ]
+  }
 }
 
 # Debug/release ----------------------------------------------------------------
 
 config("debug") {
   defines = [
     "_DEBUG",
     "DYNAMIC_ANNOTATIONS_ENABLED=1",
     "WTF_USE_DYNAMIC_ANNOTATIONS=1",
   ]
@@ skipping 83 matching lines @@
       "CoreFoundation.framework",
       "CoreGraphics.framework",
       "CoreText.framework",
       "Foundation.framework",
       "UIKit.framework",
     ]
   } else if (is_linux) {
     libs = [ "dl" ]
   }
 }