[Android] Use more specific host platforms for devil.

build/android/test_runner.py

Index: build/android/test_runner.py
diff --git a/build/android/test_runner.py b/build/android/test_runner.py
index 9f1b22e56dd19e66e84ad72b97b081383bff7490..9a74f03cc5872f922fc3c643d1615234f1ab0353 100755
--- a/build/android/test_runner.py
+++ b/build/android/test_runner.py
@@ -19,6 +19,7 @@ import unittest
 import devil_chromium
 
 from devil import base_error
+from devil import devil_env
 from devil.android import apk_helper
 from devil.android import device_blacklist
 from devil.android import device_errors
@@ -122,7 +123,7 @@ def ProcessCommonOptions(args):
   if args.adb_path:
     devil_custom_deps = {
       'adb': {
-        'android_host': [args.adb_path]
+        devil_env.GetPlatform(): [args.adb_path]
       }
     }