Add HostCachePersistenceManager for Cronet

net/dns/host_cache_unittest.cc

Index: net/dns/host_cache_unittest.cc
diff --git a/net/dns/host_cache_unittest.cc b/net/dns/host_cache_unittest.cc
index 66c0faae5e3b1a3f2a9291e94bcd5b401b0ccc14..f1ac9844b7800b5d7e1d7575ac8257e14095db99 100644
--- a/net/dns/host_cache_unittest.cc
+++ b/net/dns/host_cache_unittest.cc
@@ -704,8 +704,8 @@ TEST(HostCacheTest, SerializeAndDeserialize) {
   // Advance to t=12, ansd serialize the cache.
   now += base::TimeDelta::FromSeconds(7);
 
-  std::unique_ptr<base::ListValue> serialized_cache =
-      cache.GetAsListValue(/*include_staleness=*/false);
+  base::ListValue serialized_cache;
+  cache.GetAsListValue(&serialized_cache, /*include_staleness=*/false);
   HostCache restored_cache(kMaxCacheEntries);
 
   // Add entries for "foobar3.com" and "foobar4.com" to the cache before
@@ -720,7 +720,7 @@ TEST(HostCacheTest, SerializeAndDeserialize) {
   EXPECT_TRUE(restored_cache.Lookup(key4, now));
   EXPECT_EQ(2u, restored_cache.size());
 
-  restored_cache.RestoreFromListValue(*serialized_cache);
+  restored_cache.RestoreFromListValue(serialized_cache);
 
   HostCache::EntryStaleness stale;