Fixed spelling in test runner function.

Fixed a spelling error that was bothering me.

BUG=

Review URL: https://codereview.chromium.org/1120473002

Cr-Commit-Position: refs/heads/master@{#327625}
diff --git a/build/android/test_runner.py b/build/android/test_runner.py
index ebd5b39..b9d2a3f 100755
--- a/build/android/test_runner.py
+++ b/build/android/test_runner.py
@@ -111,7 +111,7 @@
   if args.build_directory:
     constants.SetBuildDirectory(args.build_directory)
   if args.output_directory:
-    constants.SetOutputDirectort(args.output_directory)
+    constants.SetOutputDirectory(args.output_directory)
   if args.adb_path:
     constants.SetAdbPath(args.adb_path)
   # Some things such as Forwarder require ADB to be in the environment path.