Add TaskPriority as a parameter to SequencedWorkerPool in preparation for TaskScheduler experiment.

net/disk_cache/simple/simple_backend_impl.cc

 // Copyright (c) 2013 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.
 
 #include "net/disk_cache/simple/simple_backend_impl.h"
 
 #include <algorithm>
 #include <cstdlib>
 #include <functional>
 
@@ skipping 47 matching lines @@
 
 const char kThreadNamePrefix[] = "SimpleCache";
 
 // Maximum fraction of the cache that one entry can consume.
 const int kMaxFileRatio = 8;
 
 class LeakySequencedWorkerPool {
  public:
   LeakySequencedWorkerPool()
       : sequenced_worker_pool_(
-            new SequencedWorkerPool(kMaxWorkerThreads, kThreadNamePrefix)) {}
+            new SequencedWorkerPool(kMaxWorkerThreads,
+                                    kThreadNamePrefix,
+                                    base::TaskPriority::USER_BLOCKING)) {}
 
   void FlushForTesting() { sequenced_worker_pool_->FlushForTesting(); }
 
   scoped_refptr<base::TaskRunner> GetTaskRunner() {
     return sequenced_worker_pool_->GetTaskRunnerWithShutdownBehavior(
         SequencedWorkerPool::CONTINUE_ON_SHUTDOWN);
   }
 
  private:
   scoped_refptr<SequencedWorkerPool> sequenced_worker_pool_;
@@ skipping 637 matching lines @@
 }
 
 // static
 void SimpleBackendImpl::FlushWorkerPoolForTesting() {
   // We only need to do this if we there is an active task runner.
   if (base::ThreadTaskRunnerHandle::IsSet())
     g_sequenced_worker_pool.Get().FlushForTesting();
 }
 
 }  // namespace disk_cache