Remove TabContents from TabStripModelObserver::TabReplacedAt.

chrome/browser/ui/tabs/tab_strip_model_observer.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/tabs/tab_strip_model_observer.h"
 
 using content::WebContents;
 
 void TabStripModelObserver::TabInsertedAt(WebContents* contents,
                                           int index,
@@ skipping 27 matching lines @@
                                      int from_index,
                                      int to_index) {
 }
 
 void TabStripModelObserver::TabChangedAt(WebContents* contents,
                                          int index,
                                          TabChangeType change_type) {
 }
 
 void TabStripModelObserver::TabReplacedAt(TabStripModel* tab_strip_model,
-                                          TabContents* old_contents,
-                                          TabContents* new_contents,
+                                          WebContents* old_contents,
+                                          WebContents* new_contents,
                                           int index) {
 }
 
 void TabStripModelObserver::TabPinnedStateChanged(WebContents* contents,
                                                   int index) {
 }
 
 void TabStripModelObserver::TabMiniStateChanged(WebContents* contents,
                                                 int index) {
 }
 
 void TabStripModelObserver::TabBlockedStateChanged(WebContents* contents,
                                                    int index) {
 }
 
 void TabStripModelObserver::TabStripEmpty() {}
 
 void TabStripModelObserver::TabStripModelDeleted() {}