Move instant support to SearchTabHelper. Fix InstantTab reset.

chrome/browser/ui/search/search_model.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/search/search_model.h"
 
 #include "chrome/browser/search/search.h"
 #include "chrome/browser/ui/search/search_model_observer.h"
 
 SearchModel::SearchModel() {
@@ skipping 59 matching lines @@
   if (state_.top_bars_visible == visible)
     return;
 
   const State old_state = state_;
   state_.top_bars_visible = visible;
 
   FOR_EACH_OBSERVER(SearchModelObserver, observers_,
                     ModelChanged(old_state, state_));
 }
 
+void SearchModel::SetSupportsInstant(bool supports_instant) {
+  DCHECK(chrome::IsInstantExtendedAPIEnabled())
+      << "Please do not try to set the SearchModel mode without first "
+      << "checking if Search is enabled.";
+
+  InstantSupportState new_instant_support = supports_instant ?
+      INSTANT_SUPPORT_YES : INSTANT_SUPPORT_NO;
+
+  if (state_.instant_support == new_instant_support)
+    return;
+
+  const State old_state = state_;
+  state_.instant_support = new_instant_support;
+
+  FOR_EACH_OBSERVER(SearchModelObserver, observers_,
+                    ModelChanged(old_state, state_));
+}
+
 void SearchModel::AddObserver(SearchModelObserver* observer) {
   observers_.AddObserver(observer);
 }
 
 void SearchModel::RemoveObserver(SearchModelObserver* observer) {
   observers_.RemoveObserver(observer);
 }