Re-introduce-override_build_timestamp.patch

From: csagan5 <32685696+csagan5@users.noreply.github.com>
Date: Sun, 30 Dec 2018 09:26:12 +0100
Subject: Re-introduce override_build_timestamp

Revert "Remove override_build_date gn arg."

This reverts commit e335101eedd3ab28d16dcb4b22e5ee0b60044b89.
Use (overriden) build timestamp for chrome_version_id

License: GPL-3.0-only - https://spdx.org/licenses/GPL-3.0-only.html
---
 base/BUILD.gn             | 6 +++++-
 build_overrides/build.gni | 5 +++++
 2 files changed, 10 insertions(+), 1 deletion(-)

diff --git a/base/BUILD.gn b/base/BUILD.gn
--- a/base/BUILD.gn
+++ b/base/BUILD.gn
@@ -4509,8 +4509,12 @@ if (current_toolchain == default_toolchain) {
     outputs = [ _build_date_header_internal ]
     args = [
       rebase_path(_build_date_header_internal, root_build_dir),
-      build_timestamp,
     ]
+    if (override_build_timestamp != "N/A") {
+      args += [ override_build_timestamp ]
+    } else {
+      args += [ build_timestamp ]
+    }
   }
 }
 
diff --git a/build_overrides/build.gni b/build_overrides/build.gni
--- a/build_overrides/build.gni
+++ b/build_overrides/build.gni
@@ -45,6 +45,11 @@ declare_args() {
   # //third_party/robolectric .
   limit_android_deps = false
 
+  # Override this value to give a specific build date.
+  # See //base/build_time.cc and //build/write_build_date_header.py for more
+  # details; expected format is Unix Epoch time in seconds.
+  override_build_timestamp = "N/A"
+
   # Allows googletest to pretty-print various absl types.
   gtest_enable_absl_printers = true
 }
--