alternate ntp: toolbar background and separator animation

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/ui/search/search.h"
 #include "chrome/browser/ui/search/search_model_observer.h"
 #include "chrome/browser/ui/tab_contents/tab_contents.h"
 
 namespace chrome {
 namespace search {
 
 SearchModel::SearchModel(TabContents* contents)
     : contents_(contents) {
 }
 
 SearchModel::~SearchModel() {
 }
 
-void SearchModel::SetMode(const Mode& mode) {
+void SearchModel::SetMode(const Mode& new_mode) {
   if (!contents_)
     return;
 
   DCHECK(IsInstantExtendedAPIEnabled(contents_->profile()))
       << "Please do not try to set the SearchModel mode without first "
       << "checking if Search is enabled.";
 
-  if (mode_ == mode)
+  if (mode_ == new_mode)
     return;
 
-  mode_ = mode;
+  const Mode old_mode = mode_;
+  mode_ = new_mode;
 
-  FOR_EACH_OBSERVER(SearchModelObserver, observers_, ModeChanged(mode_));
+  FOR_EACH_OBSERVER(SearchModelObserver, observers_,
+                    ModeChanged(old_mode, mode_));
 
   // Animation is transient, it is cleared after observers are notified.
   mode_.animate = false;
 }
 
 void SearchModel::MaybeChangeMode(Mode::Type from_mode, Mode::Type to_mode) {
   if (mode_.mode == from_mode) {
     Mode mode(to_mode, true);
     SetMode(mode);
   }
 }
 
 void SearchModel::AddObserver(SearchModelObserver* observer) {
   observers_.AddObserver(observer);
 }
 
 void SearchModel::RemoveObserver(SearchModelObserver* observer) {
   observers_.RemoveObserver(observer);
 }
 
 } //  namespace search
 } //  namespace chrome