alternate ntp: implement Show/HideBars API to reduce jank when showing/hiding bars

chrome/browser/ui/cocoa/browser_window_cocoa.mm

 // 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/cocoa/browser_window_cocoa.h"
 
 #include "base/bind.h"
 #include "base/command_line.h"
 #include "base/logging.h"
 #include "base/mac/mac_util.h"
@@ skipping 647 matching lines @@
     BrowserWindowCocoa::GetActiveTabPermissionGranter() {
   WebContents* web_contents =
       browser_->tab_strip_model()->GetActiveWebContents();
   if (!web_contents)
     return NULL;
   extensions::TabHelper* tab_helper =
       extensions::TabHelper::FromWebContents(web_contents);
   return tab_helper ? tab_helper->active_tab_permission_granter() : NULL;
 }
 
-void BrowserWindowCocoa::ModeChanged(
-    const chrome::search::Mode& old_mode,
-    const chrome::search::Mode& new_mode) {
+void BrowserWindowCocoa::ModelChanged(
+    const chrome::search::SearchModel::State& old_state,
+    const chrome::search::SearchModel::State& new_state) {
   [controller_ updateBookmarkBarStateForInstantOverlay];
 }
 
 void BrowserWindowCocoa::DestroyBrowser() {
   [controller_ destroyBrowser];
 
   // at this point the controller is dead (autoreleased), so
   // make sure we don't try to reference it any more.
 }
 
@@ skipping 31 matching lines @@
   PasswordGenerationBubbleController* controller =
       [[PasswordGenerationBubbleController alloc]
         initWithWindow:browser_->window()->GetNativeWindow()
             anchoredAt:point
         renderViewHost:web_contents->GetRenderViewHost()
         passwordManager:PasswordManager::FromWebContents(web_contents)
         usingGenerator:password_generator
                forForm:form];
   [controller showWindow:nil];
 }