Update Chomium's build files to work w/ latest GN binaries.

chrome_elf/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("//chrome/version.gni")
 import("//testing/test.gni")
 
 process_version("chrome_elf_resources") {
   source = "//chrome/app/chrome_version.rc.version"
   output = "$target_gen_dir/chrome_elf_version.rc"
@@ skipping 14 matching lines @@
     ":breakpad",
     ":lib",
     ":chrome_elf_resources",
   ]
   configs += [ "//build/config/win:windowed" ]
   configs -= [ "//build/config/win:console" ]
   ldflags = [
     "/NODEFAULTLIB:user32.lib",
     "/DEF:" + rebase_path("chrome_elf.def"),
   ]
-  if (cpu_arch == "x86") {
+  if (current_cpu == "x86") {
     # Don"t set an x64 base address (to avoid breaking HE-ASLR).
     ldflags += [ "/BASE:0x01c20000" ]
   }
 }
 
 source_set("lib") {
   sources = [
     "create_file/chrome_create_file.cc",
     "create_file/chrome_create_file.h",
     "ntdll_cache.cc",
@@ skipping 43 matching lines @@
   shared_library("chrome_redirects") {
     sources = [
       "chrome_redirects_main.cc",
     ]
     deps = [
       ":lib",
     ]
     configs += [ "//build/config/win:windowed" ]
     ldflags = [ "/DEF:" + rebase_path("chrome_redirects.def") ]
 
-    if (cpu_arch == "x86") {
+    if (current_cpu == "x86") {
       # Don't set an x64 base address (to avoid breaking HE-ASLR).
       ldflags += [ "/BASE:0x01c20000" ]
     }
   }
 }
 
 source_set("dll_hash") {
   deps = [
     "//base",
   ]
@@ skipping 86 matching lines @@
   ]
   ldflags = [ "/DEF:" + rebase_path("blacklist/test/blacklist_test_dll_2.def",
                                     root_build_dir) ]
 }
 
 shared_library("blacklist_test_dll_3") {
   sources = [
     "blacklist/test/blacklist_test_dll_3.cc",
   ]
 }