cronet: Fix StaleHostResolver.AddressListDelta histogram.

components/cronet/stale_host_resolver.cc

Index: components/cronet/stale_host_resolver.cc
diff --git a/components/cronet/stale_host_resolver.cc b/components/cronet/stale_host_resolver.cc
index edf011344e3abc0b2d9b843e8d04eda0a0c8ec85..7ef542ed6587fd74869ed40a718eecc73e1f62b7 100644
--- a/components/cronet/stale_host_resolver.cc
+++ b/components/cronet/stale_host_resolver.cc
@@ -298,10 +298,8 @@ int StaleHostResolver::RequestImpl::HandleResult(int rv,
                                                  net::AddressList* addresses) {

[xunjieli, 2016/11/01 21:14:16]

Can we change the argument from pointer to const ref? 
same for ReturnResult().

[Julia Tuttle, 2016/11/02 16:33:41]

Done.

   DCHECK(result_addresses_);
 
-  if (rv == net::OK) {
+  if (rv == net::OK)
     *result_addresses_ = *addresses;
-    addresses->clear();
-  }
   result_addresses_ = nullptr;
   return rv;
 }