Emit logcats for ui_base_unittests.

ui/base/ui_base_unittests_apk.isolate

 # 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.
 {
   'includes': [
     '../../build/android/android.isolate',
     'ui_base_tests.isolate'
   ],
   'variables': {
     'command': [
       '<(PRODUCT_DIR)/bin/run_ui_base_unittests',
+      '--logcat-output-dir', '${ISOLATED_OUTDIR}/logcats',
     ],
     'files': [
       '../../third_party/icu/icu.isolate',
       '<(PRODUCT_DIR)/bin/run_ui_base_unittests',
       '<(PRODUCT_DIR)/ui_base_unittests_apk/',
       'ui_base_tests.isolate',
     ]
   },
 }