**STILLBAKING** Decouple disk cache tests from backends.

net/disk_cache/backend_tests.h

Index: net/disk_cache/backend_tests.h
diff --git a/net/disk_cache/backend_tests.h b/net/disk_cache/backend_tests.h
new file mode 100644
index 0000000000000000000000000000000000000000..c448bb1b64973616e67a7a982f15a8b39118810a
--- /dev/null
+++ b/net/disk_cache/backend_tests.h
@@ -0,0 +1,16 @@
+// Copyright (c) 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 NET_DISK_CACHE_BACKEND_TESTS_H_
+#define NET_DISK_CACHE_BACKEND_TESTS_H_
+
+#include "net/disk_cache/disk_cache_test.h"
+
+namespace disk_cache {
+
+class DiskCacheBackendTest : public DiskCacheTest {};
+
+}  // namespace disk_cache
+
+#endif  // NET_DISK_CACHE_ENTRY_TESTS_H_