[Instant] Default Search Provider change redirects to local NTP in some cases

chrome/browser/search/instant_service_observer.h

Index: chrome/browser/search/instant_service_observer.h
diff --git a/chrome/browser/search/instant_service_observer.h b/chrome/browser/search/instant_service_observer.h
index 68b4c973196b403b5fe73c076628d199eb02f329..d38337d52062e150754796b9f5318d5d545b3cd6 100644
--- a/chrome/browser/search/instant_service_observer.h
+++ b/chrome/browser/search/instant_service_observer.h
@@ -20,8 +20,11 @@ class InstantServiceObserver {
   virtual void MostVisitedItemsChanged(
       const std::vector<InstantMostVisitedItem>&);
 
-  // Indicates that the default search provider changed.
-  virtual void DefaultSearchProviderChanged();
+  // Indicates that the default search provider changed. Parameter indicates
+  // whether the Google base URL changed (such as when the user migrates from
+  // one google.<TLD> to another TLD).
+  virtual void DefaultSearchProviderChanged(
+      bool google_base_url_domain_changed);
 
   // Indicates that the omnibox start margin has changed.
   virtual void OmniboxStartMarginChanged(int omnibox_start_margin);