Makes GetBuildTime behave identically on all build types.

base/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.
 
 # HOW TO WRITE CONDITIONALS IN THIS FILE
 # ======================================
 #
 # In many other places, one would write a conditional that expresses all the
 # cases when a source file is used or unused, and then either add or subtract
 # it from the sources list in that case
 #
 # Since base includes so many low-level things that vary widely and
 # unpredictably for the various build types, we prefer a slightly different
 # style. Instead, there are big per-platform blocks of inclusions and
 # exclusions. If a given file has an inclusion or exclusion rule that applies
 # for multiple conditions, perfer to duplicate it in both lists. This makes it
 # a bit easier to see which files apply in which cases rather than having a
 # huge sequence of random-looking conditionals.
 
 import("//build/buildflag_header.gni")
 import("//build/config/compiler/compiler.gni")
 import("//build/config/nacl/config.gni")
 import("//build/config/ui.gni")
 import("//build/nocompile.gni")
 import("//testing/test.gni")
 
 declare_args() {
+  # Override this value to give a specific build date.
+  # See //base/build_time.cc for more details.
+  override_build_date = "N/A"
+
   # Whether to disable the handle verifier hooks.
   # Hookless parts of the handle verifier will still function.
   win_disable_handle_verifier_hooks = false
 }
 
 if (is_android) {
   import("//build/config/android/rules.gni")
 }
 
 config("base_flags") {
@@ skipping 924 matching lines @@
 
   deps = [
     "//base/allocator",
     "//base/third_party/dynamic_annotations",
     "//third_party/modp_b64",
   ]
 
   public_deps = [
     ":base_paths",
     ":base_static",
+    ":build_date",
     ":debugging_flags",
   ]
 
   # Allow more direct string conversions on platforms with native utf8
   # strings
   if (is_mac || is_ios || is_chromeos) {
     defines += [ "SYSTEM_NATIVE_UTF8" ]
   }
 
   # Android.
@@ skipping 912 matching lines @@
       data += [ "$root_out_dir/base_unittests.dSYM/" ]
     }
   }
 
   # This disables one of the handle verifier tests.
   if (is_win && win_disable_handle_verifier_hooks) {
     defines = [ "DISABLE_HANDLE_VERIFIER_HOOKS" ]
   }
 }
 
+action("build_date") {
+  script = "//build/write_build_date_header.py"
+  outputs = [
+    "$target_gen_dir/generated_build_date.h",
+  ]
+
+  args =
+      [ rebase_path("$target_gen_dir/generated_build_date.h", root_build_dir) ]
+
+  if (is_official_build) {
+    args += [ "official" ]
+  } else {
+    args += [ "default" ]
+  }
+
+  if (override_build_date != "N/A") {
+    args += [ override_build_date ]
+  }
+}
+
 if (enable_nocompile_tests) {
   nocompile_test("base_nocompile_tests") {
     sources = [
       "bind_unittest.nc",
       "callback_list_unittest.nc",
       "callback_unittest.nc",
       "memory/scoped_ptr_unittest.nc",
       "memory/weak_ptr_unittest.nc",
     ]
 
@@ skipping 150 matching lines @@
 
   # GYP: //base.gyp:base_java_unittest_support
   android_library("base_java_unittest_support") {
     deps = [
       ":base_java",
     ]
     java_files =
         [ "test/android/java/src/org/chromium/base/ContentUriTestUtils.java" ]
   }
 }