Remove WorkerPool dependency from URLRequestFileJob.

cloud_print/service/service_state.cc

Index: cloud_print/service/service_state.cc
diff --git a/cloud_print/service/service_state.cc b/cloud_print/service/service_state.cc
index f2baddef2528631f602f61f7cc83fbc8d2576577..4246b2a81cccf3bc130c889627481d304e7b520d 100644
--- a/cloud_print/service/service_state.cc
+++ b/cloud_print/service/service_state.cc
@@ -10,6 +10,7 @@
 #include "base/message_loop/message_loop.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
+#include "base/threading/worker_pool.h"
 #include "net/base/escape.h"
 #include "net/base/io_buffer.h"
 #include "net/base/load_flags.h"
@@ -162,7 +163,8 @@ std::string ServiceState::LoginToGoogle(const std::string& service,
                                         const std::string& password) {
   base::MessageLoop loop(base::MessageLoop::TYPE_IO);
 
-  net::URLRequestContextBuilder builder;
+  net::URLRequestContextBuilder builder(
+      base::WorkerPool::GetTaskRunner(true /* task_is_slow */));
   scoped_ptr<net::URLRequestContext> context(builder.Build());
 
   ServiceStateURLRequestDelegate fetcher_delegate;