Remove TabContents from constrained windows.

chrome/browser/ui/cocoa/constrained_web_dialog_delegate_mac.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/webui/constrained_web_dialog_delegate_base.h"
 
 #import <Cocoa/Cocoa.h>
 
 #include "base/memory/scoped_nsobject.h"
 #include "chrome/browser/ui/cocoa/constrained_window_mac.h"
@@ skipping 110 matching lines @@
         Profile* profile,
         WebDialogDelegate* delegate,
         WebDialogWebContentsDelegate* tab_delegate,
         TabContents* tab_contents) {
   // Deleted when ConstrainedWebDialogDelegateMac::DeleteDelegate() runs.
   ConstrainedWebDialogDelegateMac* constrained_delegate =
       new ConstrainedWebDialogDelegateMac(profile, delegate, tab_delegate);
   // Deleted when ConstrainedWebDialogDelegateMac::OnDialogCloseFromWebUI()
   // runs.
   ConstrainedWindow* constrained_window =
-      new ConstrainedWindowMac(tab_contents, constrained_delegate);
+      new ConstrainedWindowMac(tab_contents->web_contents(),
+                               constrained_delegate);
   constrained_delegate->set_window(constrained_window);
   return constrained_delegate;
 }
 
 @implementation ConstrainedWebDialogSheetCocoa
 
 - (id)initWithConstrainedWebDialogDelegateMac:
     (ConstrainedWebDialogDelegateMac*)ConstrainedWebDialogDelegateMac {
   if ((self = [super init]))
     constrainedWebDelegate_ = ConstrainedWebDialogDelegateMac;
   return self;
 }
 
 - (void)sheetDidEnd:(NSWindow*)sheet
          returnCode:(int)returnCode
         contextInfo:(void *)contextInfo {
   [sheet orderOut:self];
 }
 
 @end