Remove ImageLoadingTracker class

chrome/browser/ui/cocoa/infobars/extension_infobar_controller.mm

 // 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.
 
 #import "chrome/browser/ui/cocoa/infobars/extension_infobar_controller.h"
 
 #include <cmath>
 
 #include "chrome/browser/api/infobars/infobar_service.h"
 #include "chrome/browser/extensions/extension_host.h"
@@ skipping 65 matching lines @@
                                    ExtensionIconSet::MATCH_EXACTLY);
     extensions::ImageLoader* loader =
         extensions::ImageLoader::Get(delegate_->extension_host()->profile());
     loader->LoadImageAsync(extension, icon_resource,
                            gfx::Size(extension_misc::EXTENSION_ICON_BITTY,
                                      extension_misc::EXTENSION_ICON_BITTY),
                            base::Bind(&InfobarBridge::OnImageLoaded,
                                       weak_ptr_factory_.GetWeakPtr()));
   }
 
-  // ImageLoadingTracker::Observer implementation.
+  // ImageLoader callback.
   // TODO(andybons): The infobar view implementations share a lot of the same
   // code. Come up with a strategy to share amongst them.
   void OnImageLoaded(const gfx::Image& image) {
     if (!delegate_)
       return;  // The delegate can go away while the image asynchronously loads.
 
     ResourceBundle& rb = ResourceBundle::GetSharedInstance();
 
     // Fall back on the default extension icon on failure.
     const gfx::ImageSkia* icon;
@@ skipping 175 matching lines @@
 
 InfoBar* ExtensionInfoBarDelegate::CreateInfoBar(InfoBarService* owner) {
   NSWindow* window =
       [(NSView*)owner->GetWebContents()->GetContentNativeView() window];
   ExtensionInfoBarController* controller =
       [[ExtensionInfoBarController alloc] initWithDelegate:this
                                                      owner:owner
                                                     window:window];
   return new InfoBar(controller, this);
 }