Eliminate all UI thread decoding of extension images....

chrome/browser/views/infobars/extension_infobar.h

Index: chrome/browser/views/infobars/extension_infobar.h
===================================================================
--- chrome/browser/views/infobars/extension_infobar.h	(revision 42429)
+++ chrome/browser/views/infobars/extension_infobar.h	(working copy)
@@ -7,6 +7,7 @@
 
 #include "chrome/browser/views/infobars/infobars.h"
 
+#include "chrome/browser/extensions/image_loading_tracker.h"
 #include "chrome/browser/views/extensions/extension_view.h"
 #include "views/controls/menu/view_menu_delegate.h"
 
@@ -21,6 +22,7 @@
 // This class implements InfoBars for Extensions.
 class ExtensionInfoBar : public InfoBar,
                          public ExtensionView::Container,
+                         public ImageLoadingTracker::Observer,
                          public views::ViewMenuDelegate {
  public:
   explicit ExtensionInfoBar(ExtensionInfoBarDelegate* delegate);
@@ -34,6 +36,10 @@
   // Overridden from views::View:
   virtual void Layout();
 
+  // Overridden from ImageLoadingTracker::Observer:
+  virtual void OnImageLoaded(
+      SkBitmap* image, ExtensionResource resource, int index);
+
   // Overridden from views::ViewMenuDelegate:
   virtual void RunMenu(View* source, const gfx::Point& pt);
 
@@ -51,6 +57,9 @@
   scoped_ptr<views::Menu2> options_menu_menu_;
   views::MenuButton* menu_;
 
+  // Keeps track of images being loaded on the File thread.
+  ImageLoadingTracker tracker_;
+
   DISALLOW_COPY_AND_ASSIGN(ExtensionInfoBar);
 };