Regularize storage monitor creation in Windows.

base/threading/sequenced_worker_pool.h

Index: base/threading/sequenced_worker_pool.h
diff --git a/base/threading/sequenced_worker_pool.h b/base/threading/sequenced_worker_pool.h
index a96cd76d93c19b4b453875bf54923846f50cfafc..7e04b071428c838dfcec0faa647f82baf2932045 100644
--- a/base/threading/sequenced_worker_pool.h
+++ b/base/threading/sequenced_worker_pool.h
@@ -57,10 +57,10 @@ class SequencedTaskRunner;
 // These will be executed in an unspecified order. The order of execution
 // between tasks with different sequence tokens is also unspecified.
 //
-// This class is designed to be leaked on shutdown to allow the
-// CONTINUE_ON_SHUTDOWN behavior to be implemented. To enforce the
-// BLOCK_SHUTDOWN behavior, you must call Shutdown() which will wait until
-// the necessary tasks have completed.
+// This class may be leaked on shutdown to facilitate fast shutdown. The
+// expected usage, however, is to call Shutdown(), which correctly accounts
+// for CONTINUE_ON_SHUTDOWN behavior and is required for BLOCK_SHUTDOWN
+// behavior.
 //
 // Implementation note: This does not use a base::WorkerPool since that does
 // not enforce shutdown semantics or allow us to specify how many worker