Simplify checking for prefetch field trial in RDH

chrome/browser/prefetch/prefetch.h

Index: chrome/browser/prefetch/prefetch.h
diff --git a/chrome/browser/prefetch/prefetch.h b/chrome/browser/prefetch/prefetch.h
deleted file mode 100644
index ab9fc88e9026f0e17663c8405e45d6d1f223556a..0000000000000000000000000000000000000000
--- a/chrome/browser/prefetch/prefetch.h
+++ /dev/null
@@ -1,19 +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.
-
-#ifndef CHROME_BROWSER_PREFETCH_PREFETCH_H_
-#define CHROME_BROWSER_PREFETCH_PREFETCH_H_
-
-namespace content {
-class ResourceContext;
-}
-
-namespace prefetch {
-
-// To be executed on the IO thread only.
-bool IsPrefetchEnabled(content::ResourceContext* resource_context);
-
-}  // namespace prefetch
-
-#endif  // CHROME_BROWSER_PREFETCH_PREFETCH_H_