Enable WPO for the x64 Official builds.

chrome/installer/mini_installer/BUILD.gn

 # Copyright 2015 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/features.gni")
 import("//build/config/ui.gni")
 import("//build_overrides/v8.gni")
 import("//chrome/version.gni")
 import("//third_party/icu/config.gni")
 import("//ui/base/ui_features.gni")
@@ skipping 147 matching lines @@
   ]
 }
 
 executable("mini_installer") {
   sources = [
     "mini_installer.cc",
     packed_files_rc_file,
   ]
 
   # This target is special so we manually override most linker flags and
-  # specify our own to keep the size down.
+  # specify our own to keep the size down. Also make sure that we don't use
+  # WPO as it's not supported by the mini installer.
   configs -= [
+    "//build/config/compiler:default_optimization",
     "//build/config:executable_config",
     "//build/config/win:console",
   ]
   configs += [
     ":mini_installer_compiler_flags",
+    "//build/config/compiler:optimize_no_wpo",
     "//build/config/win:sdk_link",
     "//build/config/win:windowed",
   ]
 
   ldflags = [
     "/ENTRY:MainEntryPoint",
     "/FIXED:NO",
     "/ignore:4199",
     "/NXCOMPAT",
   ]
@@ skipping 25 matching lines @@
     args = [
       "--out",
       "$target_name.exe",
     ]
     deps = [
       ":mini_installer",
       "//chrome/installer/test:alternate_version_generator",
     ]
   }
 }