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

components/webcrypto/webcrypto_impl.cc

Index: components/webcrypto/webcrypto_impl.cc
diff --git a/components/webcrypto/webcrypto_impl.cc b/components/webcrypto/webcrypto_impl.cc
index 7986b7741148e12e16ede9dbc6b392352cf098f5..d29807960d85000377bd6a2c156a30d9a492bf03 100644
--- a/components/webcrypto/webcrypto_impl.cc
+++ b/components/webcrypto/webcrypto_impl.cc
@@ -72,7 +72,10 @@ namespace {
 class CryptoThreadPool {
  public:
   CryptoThreadPool()
-      : worker_pool_(new base::SequencedWorkerPool(1, "WebCrypto")),
+      : worker_pool_(
+            new base::SequencedWorkerPool(1,
+                                          "WebCrypto",
+                                          base::TaskPriority::USER_BLOCKING)),
         task_runner_(worker_pool_->GetSequencedTaskRunnerWithShutdownBehavior(
             worker_pool_->GetSequenceToken(),
             base::SequencedWorkerPool::CONTINUE_ON_SHUTDOWN)) {}