[Android] Revise devil environment handling of host dependencies.

build/android/devil/devil_env.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.
 
 import contextlib
 import json
 import logging
 import os
+import platform
 import sys
 import tempfile
 import threading
 
 # TODO(jbudorick): Update this once dependency_manager moves to catapult.
 CATAPULT_BASE_PATH = os.path.abspath(os.path.join(
     os.path.dirname(__file__), os.pardir, os.pardir, os.pardir,
     'tools', 'telemetry'))
 
 @contextlib.contextmanager
@@ skipping 11 matching lines @@
   from catapult_base import dependency_manager # pylint: disable=import-error
 
 _ANDROID_BUILD_TOOLS = {'aapt', 'dexdump', 'split-select'}
 
 _DEVIL_DEFAULT_CONFIG = os.path.abspath(os.path.join(
     os.path.dirname(__file__), 'devil_dependencies.json'))
 
 _LEGACY_ENVIRONMENT_VARIABLES = {
   'ADB_PATH': {
     'dependency_name': 'adb',
-    'platform': 'android_linux2',
+    'platform': 'linux_x86_64',
   },
   'ANDROID_SDK_ROOT': {
     'dependency_name': 'android_sdk',
-    'platform': 'android_linux2',
+    'platform': 'linux_x86_64',
   },
 }
 
 
 def _GetEnvironmentVariableConfig():
   path_config = (
       (os.environ.get(k), v)
       for k, v in _LEGACY_ENVIRONMENT_VARIABLES.iteritems())
   return {
     'config_type': 'BaseConfig',
@@ skipping 74 matching lines @@
       self.FetchPath('android_build_tools_libc++', arch=arch, device=device)
     return self._dm.FetchPath(dependency, GetPlatform(arch, device))
 
   def LocalPath(self, dependency, arch=None, device=None):
     if self._dm is None:
       self.Initialize()
     return self._dm.LocalPath(dependency, GetPlatform(arch, device))
 
 
 def GetPlatform(arch=None, device=None):
-  if not arch:
-    arch = device.product_cpu_abi if device else sys.platform
-  return 'android_%s' % arch
+  if device:
+    return 'android_%s' % (arch or device.product_cpu_abi)
+  return 'linux_%s' % platform.machine()
 
 
 config = _Environment()