Make __DATE__, __TIME__ and __TIMESTAMP__ to evaluate to an empty string.

build/config/compiler/BUILD.gn

Index: build/config/compiler/BUILD.gn
diff --git a/build/config/compiler/BUILD.gn b/build/config/compiler/BUILD.gn
index 9d651ad27157f85f6aa0d723bf677abf284e614a..16d58a7197f1ee9fe96078c506004ad8d67d1954 100644
--- a/build/config/compiler/BUILD.gn
+++ b/build/config/compiler/BUILD.gn
@@ -180,6 +180,16 @@ config("compiler") {
     # Common GCC compiler flags setup.
     # --------------------------------
     cflags += [ "-fno-strict-aliasing" ]  # See http://crbug.com/32204
+
+    # Eliminate build metadata (__DATE__, __TIME__ and __TIMESTAMP__) for
+    # deterministic build.  See https://crbug.com/314403
+    cflags += [
+      "-Wno-builtin-macro-redefined",
+      "-D__DATE__=",
+      "-D__TIME__=",
+      "-D__TIMESTAMP__=",
+    ]
+

[Nico, 2017/01/31 01:27:56]

Don't we want this on Windows too?

[Yoshisato Yanagisawa, 2017/02/01 07:56:50]

Done.

     cflags_cc += [
       # If this is removed then remove the corresponding /Zc:threadSafeInit- for
       # Windows.