Add a new GetInstance() method for singleton classes under chrome/service and /net.

net/url_request/https_prober.cc

Index: net/url_request/https_prober.cc
diff --git a/net/url_request/https_prober.cc b/net/url_request/https_prober.cc
index 4388294feb90619b965890bcd75d1d2b1ff21987..bdafcf6e4eef5d6bf1c121c995e001756dc4ffde 100644
--- a/net/url_request/https_prober.cc
+++ b/net/url_request/https_prober.cc
@@ -2,6 +2,7 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+#include "base/singleton.h"
 #include "net/url_request/https_prober.h"
 
 #include "net/url_request/url_request.h"
@@ -15,6 +16,11 @@ HTTPSProber::HTTPSProber() {
 HTTPSProber::~HTTPSProber() {
 }
 
+// static
+HTTPSProber* HTTPSProber::GetInstance() {
+  return Singleton<HTTPSProber>::get();
+}
+
 bool HTTPSProber::HaveProbed(const std::string& host) const {
   return probed_.find(host) != probed_.end();
 }