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

chrome/browser/search_engines/search_host_to_urls_map.cc

Index: chrome/browser/search_engines/search_host_to_urls_map.cc
diff --git a/chrome/browser/search_engines/search_host_to_urls_map.cc b/chrome/browser/search_engines/search_host_to_urls_map.cc
index cb91724a0bb10044d9667a4f5c95fbb5f6644799..639c7c631a928680d3e04e04055aa68d79576cd5 100644
--- a/chrome/browser/search_engines/search_host_to_urls_map.cc
+++ b/chrome/browser/search_engines/search_host_to_urls_map.cc
@@ -41,11 +41,12 @@ void SearchHostToURLsMap::Add(const TemplateURL* template_url,
   host_to_urls_map_[url.host()].insert(template_url);
 }
 
-void SearchHostToURLsMap::Remove(const TemplateURL* template_url) {
+void SearchHostToURLsMap::Remove(const TemplateURL* template_url,
+                                 Profile* profile) {
   DCHECK(initialized_);
   DCHECK(template_url);
 
-  const GURL url(TemplateURLService::GenerateSearchURL(template_url));
+  const GURL url(TemplateURLService::GenerateSearchURL(template_url, profile));
   if (!url.is_valid() || !url.has_host())
     return;
 
@@ -62,11 +63,12 @@ void SearchHostToURLsMap::Remove(const TemplateURL* template_url) {
 
 void SearchHostToURLsMap::Update(const TemplateURL* existing_turl,
                                  const TemplateURL& new_values,
-                                 const SearchTermsData& search_terms_data) {
+                                 const SearchTermsData& search_terms_data,
+                                 Profile* profile) {
   DCHECK(initialized_);
   DCHECK(existing_turl);
 
-  Remove(existing_turl);
+  Remove(existing_turl, profile);
 
   // Use the information from new_values but preserve existing_turl's id.
   TemplateURLID previous_id = existing_turl->id();