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

net/url_request/url_request_job_manager.cc

Index: net/url_request/url_request_job_manager.cc
diff --git a/net/url_request/url_request_job_manager.cc b/net/url_request/url_request_job_manager.cc
index 1bc0be1214a15276126e08f4b1942b4e44951d9c..df425533d776d051823c9d84f8d64330b8b5e3b6 100644
--- a/net/url_request/url_request_job_manager.cc
+++ b/net/url_request/url_request_job_manager.cc
@@ -45,6 +45,11 @@ URLRequestJobManager::URLRequestJobManager() : enable_file_access_(false) {
 
 URLRequestJobManager::~URLRequestJobManager() {}
 
+// static
+URLRequestJobManager* URLRequestJobManager::GetInstance() {
+  return Singleton<URLRequestJobManager>::get();
+}
+
 URLRequestJob* URLRequestJobManager::CreateJob(net::URLRequest* request) const {
 #ifndef NDEBUG
   DCHECK(IsAllowedThread());