ServiceWorker: Fix a jumbo build error

A jumbo build error occurs since https://crrev.com/c/933867. It is
caused by the same name conflict in the anonymous namespace. Please see
the following CL and comments there.
  - https://crrev.com/c/940641

So, this patch simply resolves the name conflict by removing `using`
statement in service_worker_version.cc.

TBR=leon.han@intel.com,shimazu@chromium.org

Bug: none
Change-Id: Iebb3ecc7f0295ff48fdf724429edd538da465249
Reviewed-on: https://chromium-review.googlesource.com/957568
Commit-Queue: Jinho Bang <jinho.bang@samsung.com>
Reviewed-by: Jinho Bang <jinho.bang@samsung.com>
Cr-Commit-Position: refs/heads/master@{#542345}

content/browser/service_worker/service_worker_version.cc

@@ -52,9 +52,6 @@
 #include "third_party/WebKit/public/web/WebConsoleMessage.h"
 
 namespace content {
-
-using StatusCallback = ServiceWorkerVersion::StatusCallback;
-
 namespace {
 
 // Timeout for an installed worker to start.
@@ -102,7 +99,7 @@ void RunCallbacks(ServiceWorkerVersion* version,
 
 // An adapter to run a |callback| after StartWorker.
 void RunCallbackAfterStartWorker(base::WeakPtr<ServiceWorkerVersion> version,
-                                 StatusCallback callback,
+                                 ServiceWorkerVersion::StatusCallback callback,
                                  ServiceWorkerStatusCode status) {
   if (status == SERVICE_WORKER_OK &&
       version->running_status() != EmbeddedWorkerStatus::RUNNING) {