Widget::ShouldUseNativeFrame is now meaningful on Linux.

chrome/browser/ui/views/tabs/tab.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/tab.h"
 
 #include <limits>
 
 #include "base/command_line.h"
 #include "base/debug/alias.h"
@@ skipping 1590 matching lines @@
   return chrome::ShouldTabShowMediaIndicator(
       IconCapacity(), data().mini, IsActive(), data().show_icon,
       animating_media_state_);
 }
 
 bool Tab::ShouldShowCloseBox() const {
   return chrome::ShouldTabShowCloseButton(
       IconCapacity(), data().mini, IsActive());
 }
 
+bool Tab::UsingWindowsGlass(const views::Widget* widget) const {
+#if defined(OS_WIN)
+  return widget && widget->GetTopLevelWidget()->ShouldUseNativeFrame();
+#endif
+return false;
+}
+
 double Tab::GetThrobValue() {
   bool is_selected = IsSelected();
   double min = is_selected ? kSelectedTabOpacity : 0;
   double scale = is_selected ? kSelectedTabThrobScale : 1;
 
   if (!data().mini) {
     if (tab_animation_.get() && tab_animation_->is_animating())
       return tab_animation_->GetCurrentValue() * kHoverOpacity * scale + min;
   }
 
@@ skipping 58 matching lines @@
   const int kBarPadding = 1;
   int main_bar_left = tab_active_.l_width - kBarPadding;
   int main_bar_right = width() - tab_active_.r_width + kBarPadding;
   return gfx::Rect(
       main_bar_left, 0, main_bar_right - main_bar_left, kImmersiveBarHeight);
 }
 
 void Tab::GetTabIdAndFrameId(views::Widget* widget,
                              int* tab_id,
                              int* frame_id) const {
-  if (widget && widget->GetTopLevelWidget()->ShouldUseNativeFrame()) {
+  if (UsingWindowsGlass(widget)) {
     *tab_id = IDR_THEME_TAB_BACKGROUND_V;
     *frame_id = 0;
   } else if (data().incognito) {
     *tab_id = IDR_THEME_TAB_BACKGROUND_INCOGNITO;
     *frame_id = IDR_THEME_FRAME_INCOGNITO;
 #if defined(OS_WIN)
   } else if (win8::IsSingleWindowMetroMode()) {
     *tab_id = IDR_THEME_TAB_BACKGROUND_V;
     *frame_id = 0;
 #endif
@@ skipping 65 matching lines @@
                          const gfx::ImageSkia& image) {
   DCHECK_NE(scale_factor, ui::SCALE_FACTOR_NONE);
   ImageCacheEntry entry;
   entry.resource_id = resource_id;
   entry.scale_factor = scale_factor;
   entry.image = image;
   image_cache_->push_front(entry);
   if (image_cache_->size() > kMaxImageCacheSize)
     image_cache_->pop_back();
 }