Add a URL param to indicate group selection in Instant field trial.

chrome/browser/search_engines/search_host_to_urls_map_unittest.cc

Index: chrome/browser/search_engines/search_host_to_urls_map_unittest.cc
diff --git a/chrome/browser/search_engines/search_host_to_urls_map_unittest.cc b/chrome/browser/search_engines/search_host_to_urls_map_unittest.cc
index 501b7c723143caf94b10d5fa822fa60b02886ea8..9e8216395e46d586355e489c71fdf9d5761580cf 100644
--- a/chrome/browser/search_engines/search_host_to_urls_map_unittest.cc
+++ b/chrome/browser/search_engines/search_host_to_urls_map_unittest.cc
@@ -44,7 +44,7 @@ void SearchHostToURLsMapTest::SetUp() {
   template_urls.push_back(&t_urls_[1]);
 
   provider_map_.reset(new SearchHostToURLsMap);
-  UIThreadSearchTermsData search_terms_data;
+  UIThreadSearchTermsData search_terms_data(NULL);
   provider_map_->Init(template_urls, search_terms_data);
 }
 
@@ -52,7 +52,7 @@ TEST_F(SearchHostToURLsMapTest, Add) {
   std::string new_host = "example.com";
   TemplateURL new_t_url;
   new_t_url.SetURL("http://" + new_host + "/", 0, 0);
-  UIThreadSearchTermsData search_terms_data;
+  UIThreadSearchTermsData search_terms_data(NULL);
   provider_map_->Add(&new_t_url, search_terms_data);
 
   ASSERT_EQ(&new_t_url, provider_map_->GetTemplateURLForHost(new_host));
@@ -81,7 +81,7 @@ TEST_F(SearchHostToURLsMapTest, Update) {
   TemplateURL new_values;
   new_values.SetURL("http://" + new_host + "/", 0, 0);
 
-  UIThreadSearchTermsData search_terms_data;
+  UIThreadSearchTermsData search_terms_data(NULL);
   provider_map_->Update(&t_urls_[0], new_values, search_terms_data);
 
   ASSERT_EQ(&t_urls_[0], provider_map_->GetTemplateURLForHost(new_host));
@@ -89,7 +89,7 @@ TEST_F(SearchHostToURLsMapTest, Update) {
 }
 
 TEST_F(SearchHostToURLsMapTest, UpdateGoogleBaseURLs) {
-  UIThreadSearchTermsData search_terms_data;
+  UIThreadSearchTermsData search_terms_data(NULL);
   std::string google_base_url = "google.com";
   SetGoogleBaseURL("http://" + google_base_url +"/");