net: plumb DnsRRResolver from IOThread to HttpNetworkSession.

net/http/http_cache.h

Index: net/http/http_cache.h
diff --git a/net/http/http_cache.h b/net/http/http_cache.h
index dc167152cb3e9a96f585889f5ce7c3327318d9b0..775d03540cf68e9acb9f8c1a07e323e0f435a9ce 100644
--- a/net/http/http_cache.h
+++ b/net/http/http_cache.h
@@ -41,6 +41,7 @@ class Entry;
 
 namespace net {
 
+class DnsRRResolver;
 class HostResolver;
 class HttpAuthHandlerFactory;
 class HttpNetworkDelegate;
@@ -117,6 +118,7 @@ class HttpCache : public HttpTransactionFactory,
   // The disk cache is initialized lazily (by CreateTransaction) in this case.
   // The  HttpCache takes ownership of the |backend_factory|.
   HttpCache(HostResolver* host_resolver,
+            DnsRRResolver* dnsrr_resolver,
             ProxyService* proxy_service,
             SSLConfigService* ssl_config_service,
             HttpAuthHandlerFactory* http_auth_handler_factory,