Ensure that extension resources are loaded with the correct scaling applied on Windows.

ui/base/resource/resource_bundle_win.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 "ui/base/resource/resource_bundle_win.h"
 
 #include "base/logging.h"
 #include "base/path_service.h"
 #include "base/strings/utf_string_conversions.h"
 #include "skia/ext/image_operations.h"
@@ skipping 75 matching lines @@
   scaled_image = skia::ImageOperations::Resize(
       image,
       skia::ImageOperations::RESIZE_LANCZOS3,
       scaled_size.width(),
       scaled_size.height());
   DCHECK_EQ(scaled_image.width(), scaled_size.width());
   DCHECK_EQ(scaled_image.height(), scaled_size.height());
   return scaled_image;
 }
 
-float ResourceBundle::PlatformGetImageScale() {
-  if (!gfx::IsHighDPIEnabled())
-    return ui::GetImageScale(GetMaxScaleFactor());
-  return gfx::win::GetDeviceScaleFactor();
-}
-
 void SetResourcesDataDLL(HINSTANCE handle) {
   resources_data_dll = handle;
 }
 
 HICON LoadThemeIconFromResourcesDataDLL(int icon_id) {
   return ::LoadIcon(GetCurrentResourceDLL(), MAKEINTRESOURCE(icon_id));
 }
 
 }  // namespace ui;