views: Use Tab pointer directly when calling TabStrip::tab_at.

chrome/browser/ui/views/tabs/browser_tab_strip_controller.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/views/tabs/browser_tab_strip_controller.h"
 
 #include "base/auto_reset.h"
 #include "base/command_line.h"
 #include "chrome/browser/browser_process.h"
 #include "chrome/browser/extensions/tab_helper.h"
@@ skipping 274 matching lines @@
                                                       const gfx::Point& p) {
   context_menu_contents_.reset(new TabContextMenuContents(tab, this));
   context_menu_contents_->RunMenuAt(p);
 }
 
 void BrowserTabStripController::UpdateLoadingAnimations() {
   // Don't use the model count here as it's possible for this to be invoked
   // before we've applied an update from the model (Browser::TabInsertedAt may
   // be processed before us and invokes this).
   for (int i = 0, tab_count = tabstrip_->tab_count(); i < tab_count; ++i) {
-    BaseTab* tab = tabstrip_->tab_at(i);
     if (model_->ContainsIndex(i)) {
+      Tab* tab = tabstrip_->tab_at(i);
       TabContents* contents = model_->GetTabContentsAt(i);
       tab->UpdateLoadingAnimation(
           TabContentsNetworkState(contents->web_contents()));
     }
   }
 }
 
 int BrowserTabStripController::HasAvailableDragActions() const {
   return model_->delegate()->GetDragActions();
 }
@@ skipping 276 matching lines @@
   SetTabRendererDataFromModel(contents->web_contents(), index, &data, NEW_TAB);
   tabstrip_->AddTabAt(index, data, is_active);
 }
 
 void BrowserTabStripController::UpdateLayoutType() {
   bool adjust_layout = false;
   TabStripLayoutType layout_type =
       DetermineTabStripLayout(g_browser_process->local_state(), &adjust_layout);
   tabstrip_->SetLayoutType(layout_type, adjust_layout);
 }