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

net/disk_cache/simple/simple_backend_impl.cc

Index: net/disk_cache/simple/simple_backend_impl.cc
diff --git a/net/disk_cache/simple/simple_backend_impl.cc b/net/disk_cache/simple/simple_backend_impl.cc
index 4587bf9a3f886e886acf057941bfcda4ea0dcc8e..591f3a3f6a0dd28b4ec0f79261da1041c518c0e3 100644
--- a/net/disk_cache/simple/simple_backend_impl.cc
+++ b/net/disk_cache/simple/simple_backend_impl.cc
@@ -65,7 +65,9 @@ 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(); }