linux_aura: Call MapThemeImage for resources missing in native theme

chrome/browser/ui/views/frame/browser_desktop_window_tree_host_x11.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/frame/browser_desktop_window_tree_host_x11.h"
 
 #include "chrome/browser/themes/theme_service.h"
 #include "chrome/browser/themes/theme_service_factory.h"
 #include "chrome/browser/ui/views/frame/browser_frame.h"
 #include "chrome/browser/ui/views/frame/browser_view.h"
@@ skipping 10 matching lines @@
 class DesktopThemeProvider : public ui::ThemeProvider {
  public:
   explicit DesktopThemeProvider(ThemeService* delegate)
       : delegate_(delegate) {
   }
 
   bool UsingSystemTheme() const override {
     return delegate_->UsingSystemTheme();
   }
   gfx::ImageSkia* GetImageSkiaNamed(int id) const override {
-    if (delegate_->UsingSystemTheme())
+    if (delegate_->UsingSystemTheme() && delegate_->HasCustomImage(id))
       return delegate_->GetImageSkiaNamed(id);
 
     return delegate_->GetImageSkiaNamed(
         chrome::MapThemeImage(chrome::HOST_DESKTOP_TYPE_NATIVE, id));
   }
   SkColor GetColor(int id) const override { return delegate_->GetColor(id); }
   int GetDisplayProperty(int id) const override {
     return delegate_->GetDisplayProperty(id);
   }
   bool ShouldUseNativeFrame() const override {
@@ skipping 83 matching lines @@
     BrowserDesktopWindowTreeHost::CreateBrowserDesktopWindowTreeHost(
         views::internal::NativeWidgetDelegate* native_widget_delegate,
         views::DesktopNativeWidgetAura* desktop_native_widget_aura,
         BrowserView* browser_view,
         BrowserFrame* browser_frame) {
   return new BrowserDesktopWindowTreeHostX11(native_widget_delegate,
                                              desktop_native_widget_aura,
                                              browser_view,
                                              browser_frame);
 }