Always use opaque frame for extension app windows

chrome/browser/views/tabs/tab_strip.cc

 // Copyright (c) 2010 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/views/tabs/tab_strip.h"
 
 #include "app/animation_container.h"
 #include "app/drag_drop_types.h"
 #include "app/l10n_util.h"
 #include "app/os_exchange_data.h"
@@ skipping 454 matching lines @@
           canvas->restore();
         } else {
           tab->ProcessPaint(canvas);
         }
       } else {
         selected_tab = tab;
       }
     }
   }
 
-  if (GetThemeProvider()->ShouldUseNativeFrame()) {
+  if (GetWindow()->GetNonClientView()->UseNativeFrame()) {
     // Make sure unselected tabs are somewhat transparent.
     SkPaint paint;
     paint.setColor(SkColorSetARGB(200, 255, 255, 255));
     paint.setXfermodeMode(SkXfermode::kDstIn_Mode);
     paint.setStyle(SkPaint::kFill_Style);
     canvas->FillRectInt(
         0, 0, width(),
         height() - 2,  // Visible region that overlaps the toolbar.
         paint);
   }
@@ skipping 1272 matching lines @@
   return tab_data_.size();
 }
 
 int TabStrip::TabDataIndexOfTab(Tab* tab) const {
   for (size_t i = 0; i < tab_data_.size(); ++i) {
     if (tab_data_[i].tab == tab)
       return i;
   }
   return -1;
 }