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

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>
 
 #include "base/base_export.h"
 #include "base/callback_forward.h"
 #include "base/memory/ref_counted.h"
 #include "base/sequenced_task_runner.h"
 #include "base/single_thread_task_runner.h"
 #include "base/task_runner.h"
+#include "base/task_scheduler/scheduler_worker_pool_params.h"
 #include "base/task_scheduler/task_traits.h"
 #include "base/time/time.h"
 
 namespace gin {
 class V8Platform;
 }
 
 namespace tracked_objects {
 class Location;
 }
 
 namespace base {
 
 class HistogramBase;
-class SchedulerWorkerPoolParams;
 
 // Interface for a task scheduler and static methods to manage the instance used
 // by the post_task.h API. Note: all base/task_scheduler users should go through
 // post_task.h instead of TaskScheduler except for the one callsite per process
 // which manages the process' instance.
 class BASE_EXPORT TaskScheduler {
  public:
+  struct BASE_EXPORT InitParams {
+    InitParams(
+        const SchedulerWorkerPoolParams& background_worker_pool_params_in,
+        const SchedulerWorkerPoolParams&
+            background_blocking_worker_pool_params_in,
+        const SchedulerWorkerPoolParams& foreground_worker_pool_params_in,
+        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;
@@ skipping 64 matching lines @@
   // 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);
+
   // Registers |task_scheduler| to handle tasks posted through the post_task.h
   // API for this process. For tests, prefer base::test::ScopedTaskScheduler
   // (ensures isolation).
   static void SetInstance(std::unique_ptr<TaskScheduler> task_scheduler);
 
   // Retrieve the TaskScheduler set via SetInstance() or
   // CreateAndSet(Simple|Default)TaskScheduler(). This should be used very
   // rarely; most users of TaskScheduler should use the post_task.h API. In
   // particular, refrain from doing
   //   if (!TaskScheduler::GetInstance()) {
@@ skipping 16 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_