Just use the image skia from resouce bundle for default app icon.

chrome/browser/extensions/extension_uninstall_dialog.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/extensions/extension_uninstall_dialog.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "base/message_loop/message_loop.h"
 #include "base/metrics/histogram_macros.h"
@@ skipping 23 matching lines @@
 
 namespace extensions {
 
 namespace {
 
 const char kExtensionRemovedError[] =
     "Extension was removed before dialog closed.";
 
 const char kReferrerId[] = "chrome-remove-extension-dialog";
 
-// Returns bitmap for the default icon with size equal to the default icon's
-// pixel size under maximal supported scale factor.
-SkBitmap GetDefaultIconBitmapForMaxScaleFactor(bool is_app) {
-  const gfx::ImageSkia& image =
-      is_app ? util::GetDefaultAppIcon() : util::GetDefaultExtensionIcon();
-  return image.GetRepresentation(
-      gfx::ImageSkia::GetMaxSupportedScale()).sk_bitmap();
+// Returns gfx::ImageSkia for the default icon.
+gfx::ImageSkia GetDefaultIconImage(bool is_app) {
+  return  is_app ? util::GetDefaultAppIcon() : util::GetDefaultExtensionIcon();
 }
 
 }  // namespace
 
 ExtensionUninstallDialog::ExtensionUninstallDialog(
     Profile* profile,
     ExtensionUninstallDialog::Delegate* delegate)
     : profile_(profile),
       delegate_(delegate),
       uninstall_reason_(UNINSTALL_REASON_FOR_TESTING) {
@@ skipping 39 matching lines @@
       ImageLoader::ImageRepresentation::NEVER_RESIZE,
       gfx::Size(),
       ui::SCALE_FACTOR_100P));
   loader->LoadImagesAsync(extension_.get(), images_list,
                           base::Bind(&ExtensionUninstallDialog::OnImageLoaded,
                                      AsWeakPtr(), extension_->id()));
 }
 
 void ExtensionUninstallDialog::SetIcon(const gfx::Image& image) {
   if (image.IsEmpty()) {
-    // Let's set default icon bitmap whose size is equal to the default icon's
-    // pixel size under maximal supported scale factor. If the bitmap is larger
-    // than the one we need, it will be scaled down by the ui code.
-    // TODO(tbarzic): We should use IconImage here and load the required bitmap
-    //     lazily.
-    icon_ = gfx::ImageSkia::CreateFrom1xBitmap(
-        GetDefaultIconBitmapForMaxScaleFactor(extension_->is_app()));
+    icon_ = GetDefaultIconImage(extension_->is_app());
   } else {
     icon_ = *image.ToImageSkia();
   }
 }
 
 void ExtensionUninstallDialog::OnImageLoaded(const std::string& extension_id,
                                              const gfx::Image& image) {
   const Extension* target_extension =
       ExtensionRegistry::Get(profile_)
           ->GetExtensionById(extension_id, ExtensionRegistry::EVERYTHING);
@@ skipping 76 matching lines @@
 void ExtensionUninstallDialog::HandleReportAbuse() {
   chrome::NavigateParams params(
       profile_,
       extension_urls::GetWebstoreReportAbuseUrl(extension_->id(), kReferrerId),
       ui::PAGE_TRANSITION_LINK);
   params.disposition = NEW_FOREGROUND_TAB;
   chrome::Navigate(&params);
 }
 
 }  // namespace extensions