Simplify checking for prefetch field trial in RDH

chrome/browser/prefetch/prefetch.cc

Index: chrome/browser/prefetch/prefetch.cc
diff --git a/chrome/browser/prefetch/prefetch.cc b/chrome/browser/prefetch/prefetch.cc
deleted file mode 100644
index 2c07cc9560ba0c4cee58478d4f8f1f13460afc39..0000000000000000000000000000000000000000
--- a/chrome/browser/prefetch/prefetch.cc
+++ /dev/null
@@ -1,24 +0,0 @@
-// Copyright 2014 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#include "chrome/browser/prefetch/prefetch.h"
-
-#include <string>
-
-#include "base/metrics/field_trial.h"
-#include "base/strings/string_util.h"
-#include "chrome/browser/net/prediction_options.h"
-#include "chrome/browser/prefetch/prefetch_field_trial.h"
-#include "chrome/browser/profiles/profile_io_data.h"
-#include "net/base/network_change_notifier.h"
-
-namespace prefetch {
-
-bool IsPrefetchEnabled(content::ResourceContext* resource_context) {
-  DCHECK_CURRENTLY_ON(content::BrowserThread::IO);
-
-  return !DisableForFieldTrial();
-}
-
-}  // namespace prefetch