Remove reference counting from HttpNetworkSession.

net/http/mock_http_cache.cc

Index: net/http/mock_http_cache.cc
diff --git a/net/http/mock_http_cache.cc b/net/http/mock_http_cache.cc
index d939a3d8f9692f9f6c8eeddeda0e97dd1ccc38ca..10f4c09f286fe01eaf21eb9aec7d63652e9f8f6e 100644
--- a/net/http/mock_http_cache.cc
+++ b/net/http/mock_http_cache.cc
@@ -519,13 +519,10 @@ int MockBackendFactory::CreateBackend(NetLog* net_log,
 
 //-----------------------------------------------------------------------------
 
-MockHttpCache::MockHttpCache()
-    : http_cache_(new MockNetworkLayer(), NULL, new MockBackendFactory()) {
-}
+MockHttpCache::MockHttpCache() : MockHttpCache(new MockBackendFactory()) {}
 
 MockHttpCache::MockHttpCache(HttpCache::BackendFactory* disk_cache_factory)
-    : http_cache_(new MockNetworkLayer(), NULL, disk_cache_factory) {
-}
+    : http_cache_(new MockNetworkLayer(), nullptr, disk_cache_factory, true) {}
 
 disk_cache::Backend* MockHttpCache::backend() {
   TestCompletionCallback cb;