Add TaskScheduler::InitParams and accept it in TaskSchedulerImpl constructor.

base/task_scheduler/scheduler_worker_pool_params.cc

 // Copyright 2016 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.
 
 #include "base/task_scheduler/scheduler_worker_pool_params.h"
 
 namespace base {
 
 SchedulerWorkerPoolParams::SchedulerWorkerPoolParams(
     const std::string& name,
     ThreadPriority priority_hint,
     StandbyThreadPolicy standby_thread_policy,
     int max_threads,
     TimeDelta suggested_reclaim_time,
     SchedulerBackwardCompatibility backward_compatibility)
     : name_(name),
       priority_hint_(priority_hint),
       standby_thread_policy_(standby_thread_policy),
       max_threads_(max_threads),
       suggested_reclaim_time_(suggested_reclaim_time),
       backward_compatibility_(backward_compatibility) {}
 
 SchedulerWorkerPoolParams::SchedulerWorkerPoolParams(
+    StandbyThreadPolicy standby_thread_policy,
+    int max_threads,
+    TimeDelta suggested_reclaim_time,
+    SchedulerBackwardCompatibility backward_compatibility)
+    : SchedulerWorkerPoolParams(std::string(),
+                                ThreadPriority::NORMAL,
+                                standby_thread_policy,
+                                max_threads,
+                                suggested_reclaim_time,
+                                backward_compatibility) {}
+
+SchedulerWorkerPoolParams::SchedulerWorkerPoolParams(
     const SchedulerWorkerPoolParams& other) = default;
 
 SchedulerWorkerPoolParams& SchedulerWorkerPoolParams::operator=(
     const SchedulerWorkerPoolParams& other) = default;
 
 }  // namespace base