Expose SingleThreadTaskRunnerThreadMode in post_task.h

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 <vector>
 
@@ skipping 77 matching lines @@
   // scheduling tasks using |traits|. Tasks run one at a time in posting order.
   virtual scoped_refptr<SequencedTaskRunner>
   CreateSequencedTaskRunnerWithTraits(const TaskTraits& traits) = 0;
 
   // Returns a SingleThreadTaskRunner whose PostTask invocations result in
   // scheduling tasks using |traits|. Tasks run on a single thread in posting
   // order.
   virtual scoped_refptr<SingleThreadTaskRunner>
   CreateSingleThreadTaskRunnerWithTraits(
       const TaskTraits& traits,
-      SingleThreadTaskRunnerThreadMode thread_mode =
-          SingleThreadTaskRunnerThreadMode::SHARED) = 0;
+      SingleThreadTaskRunnerThreadMode thread_mode) = 0;
 
 #if defined(OS_WIN)
   // Returns a SingleThreadTaskRunner whose PostTask invocations result in
   // scheduling tasks using |traits| in a COM Single-Threaded Apartment. Tasks
   // run in the same Single-Threaded Apartment in posting order for the returned
   // SingleThreadTaskRunner. There is not necessarily a one-to-one
   // correspondence between SingleThreadTaskRunners and Single-Threaded
   // Apartments. The implementation is free to share apartments or create new
   // apartments as necessary. In either case, care should be taken to make sure
   // COM pointers are not smuggled across apartments.
   virtual scoped_refptr<SingleThreadTaskRunner>
   CreateCOMSTATaskRunnerWithTraits(
       const TaskTraits& traits,
-      SingleThreadTaskRunnerThreadMode thread_mode =
-          SingleThreadTaskRunnerThreadMode::SHARED) = 0;
+      SingleThreadTaskRunnerThreadMode thread_mode) = 0;
 #endif  // defined(OS_WIN)
 
   // Returns a vector of all histograms available in this task scheduler.
   virtual std::vector<const HistogramBase*> GetHistograms() const = 0;
 
   // Synchronously shuts down the scheduler. Once this is called, only tasks
   // posted with the BLOCK_SHUTDOWN behavior will be run. When this returns:
   // - All SKIP_ON_SHUTDOWN tasks that were already running have completed their
   //   execution.
   // - All posted BLOCK_SHUTDOWN tasks have completed their execution.
@@ skipping 78 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_