Defer late and async scripts

Source/core/fetch/ResourceLoadPriorityOptimizer.cpp

 /*
  * Copyright (C) 2013 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 80 matching lines @@
     }
     m_objects.removeAll(objectsToRemove);
 
     updateImageResourcesWithLoadPriority();
 }
 
 void ResourceLoadPriorityOptimizer::updateImageResourcesWithLoadPriority()
 {
     for (ImageResourceMap::iterator it = m_imageResources.begin(); it != m_imageResources.end(); ++it) {
         ResourceLoadPriority priority = it->value->status == Visible ?
-            ResourceLoadPriorityLow : ResourceLoadPriorityVeryLow;
+            ResourceLoadPriorityMedium : ResourceLoadPriorityVeryLow;
 
         if (priority != it->value->imageResource->resourceRequest().priority()) {
             it->value->imageResource->mutableResourceRequest().setPriority(priority, it->value->screenArea);
             it->value->imageResource->didChangePriority(priority, it->value->screenArea);
         }
     }
     m_imageResources.clear();
 }
 
 void ResourceLoadPriorityOptimizer::notifyImageResourceVisibility(ImageResource* img, VisibilityStatus status, const LayoutRect& screenRect)
 {
     if (!img || img->isLoaded())
         return;
 
     int screenArea = 0;
     if (!screenRect.isEmpty() && status == Visible)
         screenArea += static_cast<uint32_t>(screenRect.width() * screenRect.height());
 
     ImageResourceMap::AddResult result = m_imageResources.add(img->identifier(), adoptPtr(new ResourceAndVisibility(img, status, screenArea)));
     if (!result.isNewEntry && status == Visible) {
         result.storedValue->value->status = status;
         result.storedValue->value->screenArea = status;
     }
 }
 
 }