NaCl cleanup: Use Bit('build_ARCH') instead of Bit('target_ARCH')

ppapi/native_client/chrome_main.scons

 #! -*- python -*-
 # Copyright (c) 2012 The Native Client 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 json
 import os
 import shutil
 import sys
 
@@ skipping 517 matching lines @@
     for action in post_actions:
       env.AddPostAction(node, action)
   return node
 
 pre_base_env.AddMethod(PPAPIBrowserTester)
 
 
 # Disabled for ARM and MIPS because Chrome binaries for ARM and MIPS are not
 # available.
 def PPAPIBrowserTesterIsBroken(env):
-  return env.Bit('target_arm') or env.Bit('target_mips32')
+  return env.Bit('build_arm') or env.Bit('build_mips32')
 
 pre_base_env.AddMethod(PPAPIBrowserTesterIsBroken)
 
 # 3D is disabled everywhere
 def PPAPIGraphics3DIsBroken(env):
   return True
 
 pre_base_env.AddMethod(PPAPIGraphics3DIsBroken)
 
 
 def AddChromeFilesFromGroup(env, file_group):
   env['BUILD_SCONSCRIPTS'] = ExtendFileList(
       env.get('BUILD_SCONSCRIPTS', []),
       ppapi_scons_files[file_group])
 
 pre_base_env.AddMethod(AddChromeFilesFromGroup)