GN Windows build fixes

third_party/boringssl/BUILD.gn

 # Copyright 2014 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.
 
 # Config for us and everybody else depending on BoringSSL.
 config("openssl_config") {
   include_dirs = []
   include_dirs += [ "src/include" ]
 }
 
 # Config internal to this build file.
 config("openssl_internal_config") {
   visibility = ":*"  # Only targets in this file can depend on this.
 }
 
 # The list of BoringSSL files is kept in boringssl.gypi.
 gypi_values = exec_script(
     "//build/gypi_to_gn.py",
     [ rebase_path("//third_party/boringssl/boringssl.gypi") ],
     "scope",
     [ "//third_party/boringssl/boringssl.gypi" ])
 
 component("boringssl") {
   sources = gypi_values.boringssl_lib_sources
 
   direct_dependent_configs = [ ":openssl_config" ]
 
   cflags = []
+  defines = []
 
   configs -= [ "//build/config/compiler:chromium_code" ]
   configs += [ "//build/config/compiler:no_chromium_code" ]
 
   # Also gets the include dirs from :openssl_config
   include_dirs = [
     "src/include",
     # This is for arm_arch.h, which is needed by some asm files. Since the
     # asm files are generated and kept in a different directory, they
     # cannot use relative paths to find this file.
@@ skipping 17 matching lines @@
       sources += gypi_values.boringssl_linux_x86_sources
     } else {
       defines += [ "OPENSSL_NO_ASM" ]
     }
   } else if (cpu_arch == "arm") {
     sources += gypi_values.boringssl_linux_arm_sources
   } else {
     defines += [ "OPENSSL_NO_ASM" ]
   }
 }