[Android] Use more specific host platforms for devil.

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 sys
 import tempfile
@@ skipping 19 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_host',
+    'platform': 'android_linux2',
   },
   'ANDROID_SDK_ROOT': {
     'dependency_name': 'android_sdk',
-    'platform': 'android_host',
+    'platform': 'android_linux2',
   },
 }
 
 
 def _GetEnvironmentVariableConfig():
   env_var_config = {}
   for k, v in _LEGACY_ENVIRONMENT_VARIABLES.iteritems():
     path = os.environ.get(k)
     if path:
       env_var_config[v['dependency_name']] = {
@@ skipping 58 matching lines @@
       config_files.append(_DEVIL_DEFAULT_CONFIG)
 
       self._dm = dependency_manager.DependencyManager(
           [dependency_manager.BaseConfig(c) for c in config_files])
 
   def FetchPath(self, dependency, arch=None, device=None):
     if self._dm is None:
       self.Initialize()
     if dependency in _ANDROID_BUILD_TOOLS:
       self.FetchPath('android_build_tools_libc++', arch=arch, device=device)
-    return self._dm.FetchPath(dependency, _GetPlatform(arch, 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))
+    return self._dm.LocalPath(dependency, GetPlatform(arch, device))
 
 
-def _GetPlatform(arch, device):
+def GetPlatform(arch=None, device=None):
   if not arch:
-    arch = device.product_cpu_abi if device else 'host'
+    arch = device.product_cpu_abi if device else sys.platform
   return 'android_%s' % arch
 
 
 config = _Environment()