Remove WorkerPool dependency from URLRequestFileJob.

chrome/test/chromedriver/net/url_request_context_getter.cc

Index: chrome/test/chromedriver/net/url_request_context_getter.cc
diff --git a/chrome/test/chromedriver/net/url_request_context_getter.cc b/chrome/test/chromedriver/net/url_request_context_getter.cc
index b5b4a45953fd17844ce0eded470a50e0881c1c75..aa42dee145047b0d9e4b4a13db4587baacfd6682 100644
--- a/chrome/test/chromedriver/net/url_request_context_getter.cc
+++ b/chrome/test/chromedriver/net/url_request_context_getter.cc
@@ -6,6 +6,7 @@
 
 #include <string>
 
+#include "base/threading/worker_pool.h"
 #include "net/proxy/proxy_config_service.h"
 #include "net/url_request/url_request_context.h"
 #include "net/url_request/url_request_context_builder.h"
@@ -35,7 +36,8 @@ URLRequestContextGetter::URLRequestContextGetter(
 net::URLRequestContext* URLRequestContextGetter::GetURLRequestContext() {
   CHECK(network_task_runner_->BelongsToCurrentThread());
   if (!url_request_context_) {
-    net::URLRequestContextBuilder builder;
+    net::URLRequestContextBuilder builder(
+        base::WorkerPool::GetTaskRunner(true /* task_is_slow */));
     // net::HttpServer fails to parse headers if user-agent header is blank.
     builder.set_user_agent("chromedriver");
     builder.DisableHttpCache();