Move function to compute the max number of threads in a TaskScheduler pool to base/.

base/task_scheduler/initialization_util.h

Index: base/task_scheduler/initialization_util.h
diff --git a/base/task_scheduler/initialization_util.h b/base/task_scheduler/initialization_util.h
new file mode 100644
index 0000000000000000000000000000000000000000..c4d31a0ba5560c4d0069e7dafbb4d6c8273fa920
--- /dev/null
+++ b/base/task_scheduler/initialization_util.h
@@ -0,0 +1,22 @@
+// 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_INITIALIZATION_UTIL_H_
+#define BASE_TASK_SCHEDULER_INITIALIZATION_UTIL_H_
+
+#include "base/base_export.h"
+
+namespace base {
+
+// Computes the maximum number of threads in a pool using this formula:
+//   Maximum number of threads =

[robliao, 2016/11/15 16:56:10]

This portion of the comment just restates the code. Remove this portion.

[fdoray, 2016/11/15 17:41:39]

Done.

+//    clamp(ceil(Number of cores * |cores_multiplier|) + |offset|, |min|, |max|)
+int BASE_EXPORT MaxNumberOfThreadsInPool(int min,

[robliao, 2016/11/15 16:56:10]

This isn't really a hard max. Maybe RecommendedMaxNumberOfThreadsInPool?

[fdoray, 2016/11/15 17:41:39]

? It's a hard max and not a recommendation since a pool will never have more
threads than what this returns. The returned value is used to fill the
max_threads_ member of SchedulerWorkerPoolParams, not recommended_max_threads_.

[robliao, 2016/11/15 17:57:38]

Indeed. This calculation is our opinion on how to select max_threads_ based off
of these inputs. 

Another developer can come along and misinterpret that this is the absolute
highest number that can be specified for the TaskScheduler when the opposite is
true. The TaskScheduler will respect what max_threads you give it. We just
happen to have a way of selecting a max that we think is best, but the
initializer is free to use their own judgement.

[fdoray, 2016/11/15 18:16:16]

Done.

+                                         int max,
+                                         double cores_multiplier,
+                                         int offset);

[robliao, 2016/11/15 16:56:10]

Is clang-format okay with this alignment? This is now hard enforced in base and
it didn't seem to like lined up arguments.

[fdoray, 2016/11/15 17:41:39]

This is formatted by git cl format.

+
+}  // namespace base
+
+#endif  // BASE_TASK_SCHEDULER_INITIALIZATION_UTIL_H_