Always use TaskScheduler::InitParams to initialize a TaskScheduler.

base/task_scheduler/task_scheduler.h

 // 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.
 
 #ifndef BASE_TASK_SCHEDULER_TASK_SCHEDULER_H_
 #define BASE_TASK_SCHEDULER_TASK_SCHEDULER_H_
 
 #include <memory>
 #include <string>
 #include <vector>
@@ skipping 36 matching lines @@
         const SchedulerWorkerPoolParams&
             foreground_blocking_worker_pool_params_in);
     ~InitParams();
 
     const SchedulerWorkerPoolParams background_worker_pool_params;
     const SchedulerWorkerPoolParams background_blocking_worker_pool_params;
     const SchedulerWorkerPoolParams foreground_worker_pool_params;
     const SchedulerWorkerPoolParams foreground_blocking_worker_pool_params;
   };
 
-  // Returns the index of the worker pool in which a task with |traits| should
-  // run. This should be coded in a future-proof way: new traits should
-  // gracefully map to a default pool.
-  using WorkerPoolIndexForTraitsCallback =
-      Callback<size_t(const TaskTraits& traits)>;
-
   // Destroying a TaskScheduler is not allowed in production; it is always
   // leaked. In tests, it should only be destroyed after JoinForTesting() has
   // returned.
   virtual ~TaskScheduler() = default;
 
   // Posts |task| with a |delay| and specific |traits|. |delay| can be zero.
   // For one off tasks that don't require a TaskRunner.
   virtual void PostDelayedTaskWithTraits(
       const tracked_objects::Location& from_here,
       const TaskTraits& traits,
@@ skipping 66 matching lines @@
   // new TaskScheduler.
 
 #if !defined(OS_NACL)
   // Creates and sets a task scheduler using default params. |name| is used to
   // label threads and histograms. It should identify the component that calls
   // this. CHECKs on failure. For tests, prefer base::test::ScopedTaskScheduler
   // (ensures isolation).
   static void CreateAndSetSimpleTaskScheduler(const std::string& name);
 #endif  // !defined(OS_NACL)
 
-  // Creates and sets a task scheduler with custom worker pools. CHECKs on
-  // failure. |worker_pool_params_vector| describes the worker pools to create.
-  // |worker_pool_index_for_traits_callback| returns the index in |worker_pools|
-  // of the worker pool in which a task with given traits should run. For tests,
-  // prefer base::test::ScopedTaskScheduler (ensures isolation).
-  //
-  // Deprecated. Use the overload below instead. https://crbug.com/690706
-  static void CreateAndSetDefaultTaskScheduler(
-      const std::vector<SchedulerWorkerPoolParams>& worker_pool_params_vector,
-      const WorkerPoolIndexForTraitsCallback&
-          worker_pool_index_for_traits_callback);
-
   // Creates and sets a task scheduler using custom params. |name| is used to
   // label threads and histograms. It should identify the component that creates
   // the TaskScheduler. |init_params| is used to initialize the worker pools.
   // CHECKs on failure. For tests, prefer base::test::ScopedTaskScheduler
   // (ensures isolation).
   //
   // Note: The names and priority hints in |init_params| are ignored (ref. TODO
   // to remove them).
   static void CreateAndSetDefaultTaskScheduler(const std::string& name,
                                                const InitParams& init_params);
@@ skipping 27 matching lines @@
   // each process n/GetMaxConcurrentTasksWithTraitsDeprecated() items.
   //
   // TODO(fdoray): Remove this method. https://crbug.com/687264
   virtual int GetMaxConcurrentTasksWithTraitsDeprecated(
       const TaskTraits& traits) const = 0;
 };
 
 }  // namespace base
 
 #endif  // BASE_TASK_SCHEDULER_TASK_SCHEDULER_H_