Fix auto raw pointer deduction on linux

extensions/browser/image_loader.cc

 // Copyright 2014 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 "extensions/browser/image_loader.h"
 
 #include <stddef.h>
 
 #include <map>
 #include <vector>
@@ skipping 226 matching lines @@
     const Extension* extension,
     const gfx::Size& dip_size,
     const ImageLoaderImageCallback& callback) {
   std::vector<ImageRepresentation> info_list;
 
   std::set<float> scales;
   for (auto scale : ui::GetSupportedScaleFactors())
     scales.insert(ui::GetScaleForScaleFactor(scale));
 
   // There may not be a screen in unit tests.
-  auto screen = display::Screen::GetScreen();
+  auto* screen = display::Screen::GetScreen();
   if (screen) {
     for (const auto& display : screen->GetAllDisplays())
       scales.insert(display.device_scale_factor());
   }
 
   for (auto scale : scales) {
     const gfx::Size px_size = gfx::ScaleToFlooredSize(dip_size, scale);
     ExtensionResource image = IconsInfo::GetIconResource(
         extension, px_size.width(), ExtensionIconSet::MATCH_BIGGER);
     info_list.push_back(ImageRepresentation(
@@ skipping 82 matching lines @@
        it != image_skia_map.end();
        ++it) {
     it->second.MakeThreadSafe();
     image_family.Add(it->second);
   }
 
   callback.Run(image_family);
 }
 
 }  // namespace extensions