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 5712854e557850908760ddaee65a768696d24868..13de0c9005e593347d5a104f4dacb646e0f49f59 100644
--- a/components/webcrypto/webcrypto_impl.cc
+++ b/components/webcrypto/webcrypto_impl.cc
@@ -77,7 +77,10 @@ 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)) {}