Make compiles fail when __DATE__, __TIME__, or __TIMESTAMP_ are used.

build/config/compiler/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/android/config.gni")
 import("//build/config/chrome_build.gni")
 import("//build/config/compiler/compiler.gni")
 import("//build/config/nacl/config.gni")
 import("//build/toolchain/cc_wrapper.gni")
 import("//build/toolchain/toolchain.gni")
@@ skipping 946 matching lines @@
       # for gcc 4.8.
       # TODO: remove this flag once all builds work. See crbug.com/227506
       cflags += [ "-Wno-unused-local-typedefs" ]
 
       # Don't warn about "maybe" uninitialized. Clang doesn't include this
       # in -Wall but gcc does, and it gives false positives.
       cflags += [ "-Wno-maybe-uninitialized" ]
     }
   }
 
+  if (!is_nacl && (!is_win || is_clang)) {
+    # Disable __DATE__ and __TIME__ to help make builds deterministic.
+    # Determinism is important, so we should fix compile failures rather
+    # than remove this flag (this is also why this is in :common_warnings
+    # rather than :chromium_code).
+    cflags += [ "-Wdate-time" ]
+  }
+
   # Common Clang and GCC warning setup.
   if (!is_win || is_clang) {
     cflags += [
       # Disables.
       "-Wno-missing-field-initializers",  # "struct foo f = {0};"
       "-Wno-unused-parameter",  # Unused function parameters.
     ]
   }
 
   if (is_chromeos) {
@@ skipping 604 matching lines @@
 
 if (is_ios || is_mac) {
   # On Mac and iOS, this enables support for ARC (automatic ref-counting).
   # See http://clang.llvm.org/docs/AutomaticReferenceCounting.html.
   config("enable_arc") {
     common_flags = [ "-fobjc-arc" ]
     cflags_objc = common_flags
     cflags_objcc = common_flags
   }
 }