Prevent making real DNS lookups by chrome tests.

net/http/http_network_layer_unittest.cc

Index: net/http/http_network_layer_unittest.cc
diff --git a/net/http/http_network_layer_unittest.cc b/net/http/http_network_layer_unittest.cc
index 283872d3d44b1e6243db06760cd0889d65673d6c..33891b4bedd50c9ccc68f433beaf7a7c410f3284 100644
--- a/net/http/http_network_layer_unittest.cc
+++ b/net/http/http_network_layer_unittest.cc
@@ -17,7 +17,7 @@ class HttpNetworkLayerTest : public PlatformTest {
         scoped_host_mapper_(host_mapper_.get()) {
     // TODO(darin): kill this exception once we have a way to test out the
     // HttpNetworkLayer class using loopback connections.
-    host_mapper_->AddRule("www.google.com", "www.google.com");
+    host_mapper_->AllowDirectLookup("www.google.com");
   }
 
  private: