[Android] Enable USB reset on perf bots.

scripts/slave/recipe_modules/chromium_android/api.py

 # Copyright 2013 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 datetime
 import json
 import os
 import pipes
 import re
@@ skipping 416 matching lines @@
         f.result.presentation.logs[failure] = [failure]
       f.result.presentation.status = self.m.step.EXCEPTION
 
   def device_recovery(self, restart_usb=False, **kwargs):
     args = [
         '--blacklist-file', self.blacklist_file,
         '--known-devices-file', self.known_devices_file,
         '--adb-path', self.m.adb.adb_path(),
         '-v'
     ]
+    if restart_usb:
+      args += ['--enable-usb-reset']
     self.m.step(
         'device_recovery',
         [self.m.path['checkout'].join('third_party', 'catapult', 'devil',
                                       'devil', 'android', 'tools',
                                       'device_recovery.py')] + args,
         env=self.m.chromium.get_env(),
         infra_step=True,
         **kwargs)
 
   def device_status(self, **kwargs):
@@ skipping 592 matching lines @@
                                             self.m.chromium.c.BUILD_CONFIG,
                                             'test_logs',
                                             '*.log')],
     )
 
   def common_tests_setup_steps(self, perf_setup=False,
                                remove_system_webview=False, skip_wipe=False):
     self.create_adb_symlink()
     self.spawn_logcat_monitor()
     self.authorize_adb_devices()
-    self.device_recovery()
+    # TODO(jbudorick): Restart USB only on perf bots while we
+    # figure out the fate of the usb reset in general.
+    self.device_recovery(restart_usb=perf_setup)
     if perf_setup:
       kwargs = {
           'min_battery_level': 95,
           'disable_network': True,
           'disable_java_debug': True,
           'max_battery_temp': 350}
     else:
       kwargs = {}
     if skip_wipe:
       kwargs['skip_wipe'] = True
@@ skipping 434 matching lines @@
       script = self.c.test_runner
       if wrapper_script_suite_name:
         script = self.m.chromium.output_dir.join('bin', 'run_%s' %
                                                  wrapper_script_suite_name)
       else:
         env = kwargs.get('env', {})
         env['CHROMIUM_OUTPUT_DIR'] = env.get('CHROMIUM_OUTPUT_DIR',
                                              self.m.chromium.output_dir)
         kwargs['env'] = env
       return self.m.python(step_name, script, args, **kwargs)