arc: Support non-standard display scale factors.

chrome/browser/ui/app_list/arc/arc_app_icon.h

 // Copyright 2015 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.
 
 #ifndef CHROME_BROWSER_UI_APP_LIST_ARC_ARC_APP_ICON_H_
 #define CHROME_BROWSER_UI_APP_LIST_ARC_ARC_APP_ICON_H_
 
 #include <memory>
 #include <string>
 #include <vector>
@@ skipping 72 matching lines @@
   // that new icon is available and corresponding item should invoke
   // LoadImageForScaleFactor again.
   void LoadForScaleFactor(ui::ScaleFactor scale_factor);
 
   void MaybeRequestIcon(ui::ScaleFactor scale_factor);
   static std::unique_ptr<ArcAppIcon::ReadResult> ReadOnFileThread(
       ui::ScaleFactor scale_factor,
       const base::FilePath& path,
       const base::FilePath& default_app_path);
   void OnIconRead(std::unique_ptr<ArcAppIcon::ReadResult> read_result);
-  void Update(const gfx::ImageSkia* image);
+  void Update(ui::ScaleFactor scale_factor, const SkBitmap& bitmap);
   void DiscardDecodeRequest(DecodeRequest* request);
 
   content::BrowserContext* context_;
   std::string app_id_;
   const int resource_size_in_dip_;
   Observer* observer_;
 
   Source* source_ = nullptr;  // Owned by ImageSkia storage.
   gfx::ImageSkia image_skia_;
 
   // Contains pending image decode requests.
   std::vector<std::unique_ptr<DecodeRequest>> decode_requests_;
 
   base::WeakPtrFactory<ArcAppIcon> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(ArcAppIcon);
 };
 
 #endif  // CHROME_BROWSER_UI_APP_LIST_ARC_ARC_APP_ICON_H_