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

chrome/browser/extensions/extension_install_prompt.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_install_prompt.h"
 
 #include <map>
 
 #include "base/command_line.h"
 #include "base/file_util.h"
@@ skipping 77 matching lines @@
   0,  // Bundle installs don't show OAuth permissions.
   IDS_EXTENSION_PROMPT_OAUTH_REENABLE_HEADER,
   IDS_EXTENSION_PROMPT_OAUTH_PERMISSIONS_HEADER,
 };
 
 namespace {
 
 // Size of extension icon in top left of dialog.
 const int kIconSize = 69;
 
+// 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.back();
+  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];
+
+  return Extension::GetDefaultIcon(is_app).
+      GetRepresentation(max_scale_factor).sk_bitmap();
+}
+
 }  // namespace
 
 ExtensionInstallPrompt::Prompt::Prompt(Profile* profile, PromptType type)
     : type_(type),
       extension_(NULL),
       bundle_(NULL),
       average_rating_(0.0),
       rating_count_(0),
       profile_(profile) {
 }
@@ skipping 301 matching lines @@
 void ExtensionInstallPrompt::OnInstallFailure(
     const extensions::CrxInstallerError& error) {
   install_ui_->OnInstallFailure(error);
 }
 
 void ExtensionInstallPrompt::SetIcon(const SkBitmap* image) {
   if (image)
     icon_ = *image;
   else
     icon_ = SkBitmap();
-  if (icon_.empty())
-    icon_ = Extension::GetDefaultIcon(extension_->is_app());
+  if (icon_.empty()) {
+    // 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());
+  }
 }
 
 void ExtensionInstallPrompt::OnImageLoaded(const gfx::Image& image,
                                            const std::string& extension_id,
                                            int index) {
   SetIcon(image.IsEmpty() ? NULL : image.ToSkBitmap());
   FetchOAuthIssueAdviceIfNeeded();
 }
 
 void ExtensionInstallPrompt::LoadImageIfNeeded() {
   // Bundle install prompts do not have an icon.
   if (!icon_.empty()) {
     FetchOAuthIssueAdviceIfNeeded();
     return;
   }
 
   // Load the image asynchronously. For the response, check OnImageLoaded.
   ExtensionResource image =
       extension_->GetIconResource(extension_misc::EXTENSION_ICON_LARGE,
                                   ExtensionIconSet::MATCH_BIGGER);
+  // 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.
+  // TODO(tbarzic): We should use IconImage here and load the required bitmap
+  //     lazily.
+  int pixel_size = GetSizeForMaxScaleFactor(kIconSize);
   tracker_.LoadImage(extension_, image,
-                     gfx::Size(kIconSize, kIconSize),
+                     gfx::Size(pixel_size, pixel_size),
                      ImageLoadingTracker::DONT_CACHE);
 }
 
 void ExtensionInstallPrompt::FetchOAuthIssueAdviceIfNeeded() {
   // |extension_| may be NULL, e.g. in the bundle install case.
   if (!extension_ ||
       prompt_type_ == BUNDLE_INSTALL_PROMPT ||
       prompt_type_ == INLINE_INSTALL_PROMPT ||
       prompt_.GetOAuthIssueCount() != 0U) {
     ShowConfirmation();
@@ skipping 70 matching lines @@
     Browser* browser) {
   // |browser| can be NULL in unit tests.
   if (!browser)
     return new ExtensionInstallPrompt(NULL, NULL, NULL);
   gfx::NativeWindow parent =
       browser->window() ? browser->window()->GetNativeWindow() : NULL;
   return new ExtensionInstallPrompt(parent, browser, browser->profile());
 }
 
 }  // namespace chrome