Improve performance of proxy resolver by tracing DNS dependencies.

net/http/http_network_transaction_spdy3_unittest.cc

Index: net/http/http_network_transaction_spdy3_unittest.cc
diff --git a/net/http/http_network_transaction_spdy3_unittest.cc b/net/http/http_network_transaction_spdy3_unittest.cc
index 3cc1b2c1e15c0c29ac56ae6e3c9bcdb764d7ffd0..72c885248242c562a8608efa27ad6d235512243a 100644
--- a/net/http/http_network_transaction_spdy3_unittest.cc
+++ b/net/http/http_network_transaction_spdy3_unittest.cc
@@ -7554,12 +7554,6 @@ class CapturingProxyResolver : public ProxyResolver {
     return LOAD_STATE_IDLE;
   }
 
-  virtual LoadState GetLoadStateThreadSafe(
-      RequestHandle request) const OVERRIDE {
-    NOTREACHED();
-    return LOAD_STATE_IDLE;
-  }
-
   virtual void CancelSetPacScript() {
     NOTREACHED();
   }