InstantExtended: better handling of switching between tab and overlay.

chrome/browser/ui/search/instant_controller.cc

Index: chrome/browser/ui/search/instant_controller.cc
diff --git a/chrome/browser/ui/search/instant_controller.cc b/chrome/browser/ui/search/instant_controller.cc
index e6e9bdd305e8cc1066c573e052653baed6c1c59a..aef643dc9785c579776f1d391eba1f74c6050ea5 100644
--- a/chrome/browser/ui/search/instant_controller.cc
+++ b/chrome/browser/ui/search/instant_controller.cc
@@ -294,14 +294,12 @@ InstantController::~InstantController() {
 }
 
 void InstantController::OnAutocompleteStart() {
-  if (instant_tab_ && instant_tab_->supports_instant()) {
+  if (UseTabForSuggestions() && instant_tab_->supports_instant()) {
     LOG_INSTANT_DEBUG_EVENT(
         this, "OnAutocompleteStart: using InstantTab");
     return;
   }
 
-  use_tab_for_suggestions_ = false;
-
   // Not using |instant_tab_|. Check if overlay is OK to use.
   InstantFallbackReason fallback_reason = ShouldSwitchToLocalOverlay();
   if (fallback_reason != INSTANT_FALLBACK_NONE) {
@@ -313,6 +311,7 @@ void InstantController::OnAutocompleteStart() {
     LOG_INSTANT_DEBUG_EVENT(
         this, "OnAutocompleteStart: using existing overlay");
   }
+  use_tab_for_suggestions_ = false;
 }
 
 bool InstantController::Update(const AutocompleteMatch& match,