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

chrome/browser/search_engines/template_url_service.cc

Index: chrome/browser/search_engines/template_url_service.cc
diff --git a/chrome/browser/search_engines/template_url_service.cc b/chrome/browser/search_engines/template_url_service.cc
index e60357bddb090a03ed32b8b64e33cff1e80d4127..95f3777b93ee3aa8296646305d75049a494a4ec1 100644
--- a/chrome/browser/search_engines/template_url_service.cc
+++ b/chrome/browser/search_engines/template_url_service.cc
@@ -189,14 +189,16 @@ string16 TemplateURLService::CleanUserInputKeyword(const string16& keyword) {
 }
 
 // static
-GURL TemplateURLService::GenerateSearchURL(const TemplateURL* t_url) {
+GURL TemplateURLService::GenerateSearchURL(Profile* profile,
+                                           const TemplateURL* t_url) {
   DCHECK(t_url);
   UIThreadSearchTermsData search_terms_data;
-  return GenerateSearchURLUsingTermsData(t_url, search_terms_data);
+  return GenerateSearchURLUsingTermsData(profile, t_url, search_terms_data);
 }
 
 // static
 GURL TemplateURLService::GenerateSearchURLUsingTermsData(
+    Profile* profile,
     const TemplateURL* t_url,
     const SearchTermsData& search_terms_data) {
   DCHECK(t_url);
@@ -210,7 +212,7 @@ GURL TemplateURLService::GenerateSearchURLUsingTermsData(
     return GURL(search_ref->url());
 
   return GURL(search_ref->ReplaceSearchTermsUsingTermsData(
-      *t_url, ASCIIToUTF16(kReplacementTerm),
+      profile, *t_url, ASCIIToUTF16(kReplacementTerm),
       TemplateURLRef::NO_SUGGESTIONS_AVAILABLE,
       string16(), search_terms_data));
 }