Pass QuicInMemoryCache directly instead of using a singleton.

net/tools/quic/test_tools/quic_in_memory_cache_peer.cc

Index: net/tools/quic/test_tools/quic_in_memory_cache_peer.cc
diff --git a/net/tools/quic/test_tools/quic_in_memory_cache_peer.cc b/net/tools/quic/test_tools/quic_in_memory_cache_peer.cc
deleted file mode 100644
index e342e4a39fc2626773df03bfd77e425c5ae6a875..0000000000000000000000000000000000000000
--- a/net/tools/quic/test_tools/quic_in_memory_cache_peer.cc
+++ /dev/null
@@ -1,18 +0,0 @@
-// Copyright 2013 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 "net/tools/quic/test_tools/quic_in_memory_cache_peer.h"
-
-#include "net/tools/quic/quic_in_memory_cache.h"
-
-namespace net {
-namespace test {
-
-// static
-void QuicInMemoryCachePeer::ResetForTests() {
-  QuicInMemoryCache::GetInstance()->ResetForTests();
-}
-
-}  // namespace test
-}  // namespace net