Added PrivetHTTPResolution::Start for service name only

chrome/browser/local_discovery/privet_notifications_unittest.cc

Index: chrome/browser/local_discovery/privet_notifications_unittest.cc
diff --git a/chrome/browser/local_discovery/privet_notifications_unittest.cc b/chrome/browser/local_discovery/privet_notifications_unittest.cc
index 089e3aa2615112abf6ce6bccbf5ce043926125b6..5ee723d6b89b1e7a66f59b0d2c4658b55fb529a2 100644
--- a/chrome/browser/local_discovery/privet_notifications_unittest.cc
+++ b/chrome/browser/local_discovery/privet_notifications_unittest.cc
@@ -53,6 +53,10 @@ class MockPrivetHttpFactory : public PrivetHTTPAsynchronousFactory {
           name_, net::HostPortPair("1.2.3.4", 8080), request_context_.get())));
     }
 
+    void Start(const ResultCallback& callback) override {
+      Start(net::HostPortPair(), callback);
+    }
+
     const std::string& GetName() override { return name_; }
 
    private: