[Merge M59] arc: Prevent overwriting of the Chrome Play Store icon.

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

 // 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.
 
 #include "chrome/browser/ui/app_list/arc/arc_app_icon.h"
 
 #include <algorithm>
 #include <map>
 #include <memory>
 #include <utility>
@@ skipping 240 matching lines @@
   CHECK(observer_ != nullptr);
   source_ = new Source(weak_ptr_factory_.GetWeakPtr(), resource_size_in_dip);
   gfx::Size resource_size(resource_size_in_dip, resource_size_in_dip);
   image_skia_ = gfx::ImageSkia(source_, resource_size);
 }
 
 ArcAppIcon::~ArcAppIcon() {
 }
 
 void ArcAppIcon::LoadForScaleFactor(ui::ScaleFactor scale_factor) {
-  ArcAppListPrefs* prefs = ArcAppListPrefs::Get(context_);
+  // We provide Play Store icon from Chrome resources and it is not expected
+  // that we have external load request.
+  DCHECK_NE(app_id_, arc::kPlayStoreAppId);
+
+  const ArcAppListPrefs* const prefs = ArcAppListPrefs::Get(context_);
   DCHECK(prefs);
 
-  base::FilePath path = prefs->GetIconPath(app_id_, scale_factor);
+  const base::FilePath path = prefs->GetIconPath(app_id_, scale_factor);
   if (path.empty())
     return;
 
   base::PostTaskWithTraitsAndReplyWithResult(
       FROM_HERE, base::TaskTraits().MayBlock().WithPriority(
                      base::TaskPriority::BACKGROUND),
       base::Bind(&ArcAppIcon::ReadOnFileThread, scale_factor, path,
                  prefs->MaybeGetIconPathForDefaultApp(app_id_, scale_factor)),
       base::Bind(&ArcAppIcon::OnIconRead, weak_ptr_factory_.GetWeakPtr()));
 }
@@ skipping 81 matching lines @@
   CHECK(image && !image->isNull());
 
   std::vector<gfx::ImageSkiaRep> reps = image->image_reps();
   for (const auto& image_rep : reps) {
     if (ui::IsSupportedScale(image_rep.scale())) {
       image_skia_.RemoveRepresentation(image_rep.scale());
       image_skia_.AddRepresentation(image_rep);
     }
   }
 
-  image_ = gfx::Image(image_skia_);
-
   observer_->OnIconUpdated(this);
 }
 
 void ArcAppIcon::DiscardDecodeRequest(DecodeRequest* request) {
   DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
 
   auto it = std::find_if(decode_requests_.begin(), decode_requests_.end(),
                          [request](const std::unique_ptr<DecodeRequest>& ptr) {
                            return ptr.get() == request;
                          });
   CHECK(it != decode_requests_.end());
   decode_requests_.erase(it);
 }