Update from https://crrev.com/317530

mojo/tools/mopy/gn.py

 # 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.
 
 """
 GN-related configuration functions, e.g., to produce a Config object from a GN
 args.gn file).
 """
 
 
 import ast
 import os.path
 import re
 
 from .config import Config
 
 
 def BuildDirectoryForConfig(config, src_root):
   """
   Returns the build directory for the given configuration.
   """
   subdir = ""
   if config.target_os == Config.OS_ANDROID:
     subdir += "android_"
-    if config.target_arch != Config.ARCH_ARM:
-      subdir += config.target_arch + "_"
+    if config.target_cpu != Config.ARCH_ARM:
+      subdir += config.target_cpu + "_"
   elif config.target_os == Config.OS_CHROMEOS:
     subdir += "chromeos_"
   subdir += "Debug" if config.is_debug else "Release"
   if config.sanitizer == Config.SANITIZER_ASAN:
     subdir += "_asan"
   if not(config.is_debug) and config.dcheck_always_on:
     subdir += "_dcheck"
   return os.path.join(src_root, "out", subdir)
 
 
@@ skipping 28 matching lines @@
   elif config.target_os == Config.OS_CHROMEOS:
     gn_args["os"] = "chromeos"
     gn_args["use_glib"] = False
     gn_args["use_system_harfbuzz"] = False
   elif config.target_os == Config.OS_LINUX:
     gn_args["is_desktop_linux"] = False
     gn_args["use_aura"] = False
     gn_args["use_glib"] = False
     gn_args["use_system_harfbuzz"] = False
 
-  gn_args["target_arch"] = config.target_arch
+  gn_args["target_cpu"] = config.target_cpu
 
   return gn_args
 
 
 def CommandLineForGNArgs(gn_args):
   """
   Returns the list of gn arguments to use with the gn command line.
   """
   def _ToCommandLine(key, value):
     if type(value) is bool:
@@ skipping 10 matching lines @@
   config_args = {}
   config_args["is_debug"] = args.get("is_debug", False)
   config_args["sanitizer"] = (
       Config.SANITIZER_ASAN if args.get("is_asan") else None)
   config_args["is_clang"] = args.get("is_clang", False)
   config_args["use_goma"] = args.get("use_goma", False)
   if config_args["use_goma"]:
     config_args["goma_dir"] = args.get("goma_dir")
   config_args["use_nacl"] = args.get("mojo_use_nacl", False)
   config_args["target_os"] = args.get("os")
-  config_args["target_arch"] = args.get("target_arch")
+  config_args["target_cpu"] = args.get("target_cpu")
   config_args["dcheck_always_on"] = args.get("dcheck_always_on")
   return Config(**config_args)
 
 
 def ParseGNConfig(build_dir):
   """
   Parse the gn config file present in |build_dir|. This function returns a
   dictionary with boolean values as boolean.
   """
   TRANSLATIONS = {
       "true": "True",
       "false": "False",
   }
   gn_file = os.path.join(build_dir, "args.gn")
   values = {}
   with open(gn_file, "r") as f:
     for line in f.readlines():
       line = re.sub("\s*#.*", "", line)
       result = re.match("^\s*(\w+)\s*=\s*(.*)\s*$", line)
       if result:
         key = result.group(1)
         value = result.group(2)
         values[key] = ast.literal_eval(TRANSLATIONS.get(value, value))
   return values