HostResolver is exposed to plugin.

ppapi/proxy/resource_creation_proxy.cc

Index: ppapi/proxy/resource_creation_proxy.cc
diff --git a/ppapi/proxy/resource_creation_proxy.cc b/ppapi/proxy/resource_creation_proxy.cc
index 75c41bdbfdd4c1fbf045a2f2c7c1c1e33b041d29..1f3b323bd2d784561e4d10b23d2d891ac803a7ad 100644
--- a/ppapi/proxy/resource_creation_proxy.cc
+++ b/ppapi/proxy/resource_creation_proxy.cc
@@ -23,6 +23,7 @@
 #include "ppapi/proxy/ppb_flash_net_connector_proxy.h"
 #include "ppapi/proxy/ppb_graphics_2d_proxy.h"
 #include "ppapi/proxy/ppb_graphics_3d_proxy.h"
+#include "ppapi/proxy/ppb_host_resolver_private_proxy.h"
 #include "ppapi/proxy/ppb_image_data_proxy.h"
 #include "ppapi/proxy/ppb_tcp_socket_private_proxy.h"
 #include "ppapi/proxy/ppb_udp_socket_private_proxy.h"
@@ -172,6 +173,11 @@ PP_Resource ResourceCreationProxy::CreateGraphics2D(PP_Instance instance,
                                                    is_always_opaque);
 }
 
+PP_Resource ResourceCreationProxy::CreateHostResolverPrivate(
+    PP_Instance instance) {
+  return PPB_HostResolver_Private_Proxy::CreateProxyResource(instance);
+}
+
 PP_Resource ResourceCreationProxy::CreateImageData(PP_Instance instance,
                                                    PP_ImageDataFormat format,
                                                    const PP_Size& size,