Improve performance of proxy resolver by tracing DNS dependencies.

net/http/http_network_transaction_spdy2_unittest.cc

Index: net/http/http_network_transaction_spdy2_unittest.cc
diff --git a/net/http/http_network_transaction_spdy2_unittest.cc b/net/http/http_network_transaction_spdy2_unittest.cc
index dd0683b6cd2e032896428a9582df2fdb4300c479..09742a42aced6c6f55441a115cee1ea468d4c1a8 100644
--- a/net/http/http_network_transaction_spdy2_unittest.cc
+++ b/net/http/http_network_transaction_spdy2_unittest.cc
@@ -8084,12 +8084,6 @@ class CapturingProxyResolver : public ProxyResolver {
     return LOAD_STATE_IDLE;
   }
 
-  virtual LoadState GetLoadStateThreadSafe(
-      RequestHandle request) const OVERRIDE {
-    NOTREACHED();
-    return LOAD_STATE_IDLE;
-  }
-
   virtual void CancelSetPacScript() {
     NOTREACHED();
   }