Adds InstantExtendedEnabledParam to the search request URL iff the query extraction flag is enabled.

chrome/browser/search/search.cc

Index: chrome/browser/search/search.cc
diff --git a/chrome/browser/search/search.cc b/chrome/browser/search/search.cc
index d4e8b1a604de280ee73b5b4f9694cd45f76b35c1..e53f516c29820a06126d66a3a89365a31db609d3 100644
--- a/chrome/browser/search/search.cc
+++ b/chrome/browser/search/search.cc
@@ -284,6 +284,17 @@ uint64 EmbeddedSearchPageVersion() {
   return kEmbeddedPageVersionDefault;
 }
 
+std::string InstantExtendedEnabledParam(bool for_search) {
+#if !defined(OS_IOS) && !defined(OS_ANDROID)
+  // On mobile, query extraction is always enabled.
+  if (for_search && !chrome::IsQueryExtractionEnabled())
+    return std::string();
+#endif
+
+  return std::string(google_util::kInstantExtendedAPIParam) + "=" +
+      base::Uint64ToString(EmbeddedSearchPageVersion()) + "&";
+}
+
 bool IsQueryExtractionEnabled() {
 #if defined(OS_IOS) || defined(OS_ANDROID)
   return true;