Don't set ion=1 for hidden Instant modes.

chrome/browser/search_engines/search_terms_data.cc

Index: chrome/browser/search_engines/search_terms_data.cc
diff --git a/chrome/browser/search_engines/search_terms_data.cc b/chrome/browser/search_engines/search_terms_data.cc
index 5a06cc363750c9a173ca1069b861481d638d76e8..81c17af1a7b797583410f5cd0ea29507ebb97988 100644
--- a/chrome/browser/search_engines/search_terms_data.cc
+++ b/chrome/browser/search_engines/search_terms_data.cc
@@ -8,6 +8,7 @@
 #include "base/metrics/field_trial.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/google/google_url_tracker.h"
+#include "chrome/browser/instant/instant_controller.h"
 #include "chrome/browser/instant/instant_field_trial.h"
 #include "content/public/browser/browser_thread.h"
 #include "googleurl/src/gurl.h"
@@ -45,6 +46,10 @@ std::string SearchTermsData::GoogleBaseSuggestURLValue() const {
   return base_url.ReplaceComponents(repl).spec();
 }
 
+std::string SearchTermsData::InstantEnabledParam() const {
+  return std::string();
+}
+
 std::string SearchTermsData::InstantFieldTrialUrlParam() const {
   return std::string();
 }
@@ -91,6 +96,16 @@ string16 UIThreadSearchTermsData::GetRlzParameterValue() const {
 }
 #endif
 
+std::string UIThreadSearchTermsData::InstantEnabledParam() const {
+  DCHECK(!BrowserThread::IsWellKnownThread(BrowserThread::UI) ||
+         BrowserThread::CurrentlyOn(BrowserThread::UI));
+  if (profile_ && InstantController::IsEnabled(profile_) &&
+      !InstantFieldTrial::IsHiddenExperiment(profile_)) {
+    return "&ion=1";
+  }
+  return std::string();
+}
+
 std::string UIThreadSearchTermsData::InstantFieldTrialUrlParam() const {
   DCHECK(!BrowserThread::IsWellKnownThread(BrowserThread::UI) ||
          BrowserThread::CurrentlyOn(BrowserThread::UI));