Add a class to replace ImageLoadingTracker with a nicer API.

chrome/browser/extensions/extension_install_prompt.cc

Index: chrome/browser/extensions/extension_install_prompt.cc
diff --git a/chrome/browser/extensions/extension_install_prompt.cc b/chrome/browser/extensions/extension_install_prompt.cc
index 2113b174e8bc2b98e19a8e778bfe4adee3d5044c..5444fdd76723f1bbbd7094627f43eb37086f8e85 100644
--- a/chrome/browser/extensions/extension_install_prompt.cc
+++ b/chrome/browser/extensions/extension_install_prompt.cc
@@ -16,6 +16,7 @@
 #include "chrome/browser/extensions/bundle_installer.h"
 #include "chrome/browser/extensions/extension_install_dialog.h"
 #include "chrome/browser/extensions/extension_install_ui.h"
+#include "chrome/browser/extensions/image_utils.h"
 #include "chrome/browser/prefs/pref_service.h"
 #include "chrome/browser/profiles/profile.h"
 #include "chrome/browser/signin/token_service.h"
@@ -313,8 +314,7 @@ ExtensionInstallPrompt::ExtensionInstallPrompt(
       install_ui_(ExtensionInstallUI::Create(profile)),
       delegate_(NULL),
       prompt_(profile, UNSET_PROMPT_TYPE),
-      prompt_type_(UNSET_PROMPT_TYPE),
-      ALLOW_THIS_IN_INITIALIZER_LIST(tracker_(this)) {
+      prompt_type_(UNSET_PROMPT_TYPE) {
 }
 
 ExtensionInstallPrompt::~ExtensionInstallPrompt() {
@@ -449,9 +449,7 @@ void ExtensionInstallPrompt::SetIcon(const SkBitmap* image) {
   }
 }
 
-void ExtensionInstallPrompt::OnImageLoaded(const gfx::Image& image,
-                                           const std::string& extension_id,
-                                           int index) {
+void ExtensionInstallPrompt::OnImageLoaded(const gfx::Image& image) {
   SetIcon(image.IsEmpty() ? NULL : image.ToSkBitmap());
   FetchOAuthIssueAdviceIfNeeded();
 }
@@ -472,9 +470,9 @@ void ExtensionInstallPrompt::LoadImageIfNeeded() {
   // TODO(tbarzic): We should use IconImage here and load the required bitmap
   //     lazily.
   int pixel_size = GetSizeForMaxScaleFactor(kIconSize);
-  tracker_.LoadImage(extension_, image,
-                     gfx::Size(pixel_size, pixel_size),
-                     ImageLoadingTracker::DONT_CACHE);
+  extension_image_utils::LoadImageAsync(
+      extension_, image, gfx::Size(pixel_size, pixel_size),
+      base::Bind(&ExtensionInstallPrompt::OnImageLoaded, AsWeakPtr()));
 }
 
 void ExtensionInstallPrompt::FetchOAuthIssueAdviceIfNeeded() {