Pass QuicInMemoryCache directly instead of using a singleton.

net/tools/quic/quic_in_memory_cache.cc

Index: net/tools/quic/quic_in_memory_cache.cc
diff --git a/net/tools/quic/quic_in_memory_cache.cc b/net/tools/quic/quic_in_memory_cache.cc
index 392a848b48c1f3c76db39f361ed5c17b19bb5137..8f6ec929f802948147decb868926c04ffe660dd3 100644
--- a/net/tools/quic/quic_in_memory_cache.cc
+++ b/net/tools/quic/quic_in_memory_cache.cc
@@ -155,11 +155,6 @@ void QuicInMemoryCache::ResourceFile::HandleXOriginalUrl() {
   SetHostPathFromBase(url);
 }
 
-// static
-QuicInMemoryCache* QuicInMemoryCache::GetInstance() {
-  return base::Singleton<QuicInMemoryCache>::get();
-}
-
 const QuicInMemoryCache::Response* QuicInMemoryCache::GetResponse(
     StringPiece host,
     StringPiece path) const {
@@ -231,12 +226,6 @@ void QuicInMemoryCache::AddSpecialResponse(StringPiece host,
 
 QuicInMemoryCache::QuicInMemoryCache() {}
 
-void QuicInMemoryCache::ResetForTests() {
-  base::AutoLock lock(response_mutex_);
-  responses_.clear();
-  server_push_resources_.clear();
-}
-
 void QuicInMemoryCache::InitializeFromDirectory(const string& cache_directory) {
   if (cache_directory.empty()) {
     QUIC_BUG << "cache_directory must not be empty.";