Fix for pixelated icons in extension install ui on 2x scale.

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/logging.h"
 #include "base/message_loop.h"
 #include "chrome/common/chrome_notification_types.h"
 #include "chrome/common/extensions/extension.h"
 #include "chrome/common/extensions/extension_constants.h"
 #include "chrome/common/extensions/extension_icon_set.h"
 #include "chrome/common/extensions/extension_resource.h"
 #include "content/public/browser/notification_service.h"
 #include "content/public/browser/notification_source.h"
 #include "grit/generated_resources.h"
 #include "grit/theme_resources.h"
 #include "ui/base/resource/resource_bundle.h"
 #include "ui/gfx/image/image.h"
 
+namespace {
+
+// Returns pixel size under maximal scale factor for the icon whose device
+// independent size is |size_in_dip|
+int GetSizeForMaxScaleFactor(int size_in_dip) {
+  std::vector<ui::ScaleFactor> supported_scale_factors =
+      ui::GetSupportedScaleFactors();
+  // Scale factors are in ascending order, so the last one is the one we need.
+  ui::ScaleFactor max_scale_factor =
+      supported_scale_factors[supported_scale_factors.size() - 1];
+  float max_scale_factor_scale = ui::GetScaleFactorScale(max_scale_factor);
+
+  return static_cast<int>(size_in_dip * max_scale_factor_scale);
+}
+
+// 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) {
+  std::vector<ui::ScaleFactor> supported_scale_factors =
+      ui::GetSupportedScaleFactors();
+  // Scale factors are in ascending order, so the last one is the one we need.
+  ui::ScaleFactor max_scale_factor =
+      supported_scale_factors[supported_scale_factors.size() - 1];

[Jeffrey Yasskin, 2012/09/14 19:34:01]

This should be written as supported_scale_factors.back().

[tbarzic, 2012/09/14 22:34:31]

Done.

+
+  return extensions::Extension::GetDefaultIcon(is_app).
+      GetRepresentation(max_scale_factor).sk_bitmap();
+}
+
+}  // namespace
+
 // Size of extension icon in top left of dialog.
 static const int kIconSize = 69;
 
 ExtensionUninstallDialog::ExtensionUninstallDialog(
     Browser* browser,
     ExtensionUninstallDialog::Delegate* delegate)
     : browser_(browser),
       delegate_(delegate),
       extension_(NULL),
       ui_loop_(MessageLoop::current()) {
@@ skipping 10 matching lines @@
 void ExtensionUninstallDialog::ConfirmUninstall(
     const extensions::Extension* extension) {
   DCHECK(ui_loop_ == MessageLoop::current());
   extension_ = extension;
 
   ExtensionResource image =
       extension_->GetIconResource(extension_misc::EXTENSION_ICON_LARGE,
                                   ExtensionIconSet::MATCH_BIGGER);
   // Load the image asynchronously. The response will be sent to OnImageLoaded.
   tracker_.reset(new ImageLoadingTracker(this));
+  // Load the icon whose pixel size is large enough to be displayed under
+  // maximal supported scale factor. UI code will scale the icon down if needed.
+  int pixel_size = GetSizeForMaxScaleFactor(kIconSize);
   tracker_->LoadImage(extension_, image,
-                      gfx::Size(kIconSize, kIconSize),
+                      gfx::Size(pixel_size, pixel_size),
                       ImageLoadingTracker::DONT_CACHE);
 }
 
 void ExtensionUninstallDialog::SetIcon(const gfx::Image& image) {
   if (image.IsEmpty()) {
-    if (extension_->is_app()) {
-      icon_ = *ResourceBundle::GetSharedInstance().GetImageSkiaNamed(
-          IDR_APP_DEFAULT_ICON);
-    } else {
-      icon_ = *ResourceBundle::GetSharedInstance().GetImageSkiaNamed(
-          IDR_EXTENSION_DEFAULT_ICON);
-    }
+    // 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.
+    icon_ = GetDefaultIconBitmapForMaxScaleFactor(extension_->is_app());
   } else {
     icon_ = *image.ToImageSkia();
   }
 }
 
 void ExtensionUninstallDialog::OnImageLoaded(const gfx::Image& image,
                                              const std::string& extension_id,
                                              int index) {
   SetIcon(image);
 
@@ skipping 11 matching lines @@
   DCHECK(type == chrome::NOTIFICATION_BROWSER_CLOSING);
 
   browser_ = NULL;
   if (tracker_.get()) {
     // If we're waiting for the icon, stop doing so because we're not going to
     // show the dialog.
     tracker_.reset();
     delegate_->ExtensionUninstallCanceled();
   }
 }