Change Lo-Fi bool to bitmask to support multiple Previews types

third_party/WebKit/Source/core/loader/resource/ImageResource.cpp

 /*
     Copyright (C) 1998 Lars Knoll (knoll@mpi-hd.mpg.de)
     Copyright (C) 2001 Dirk Mueller (mueller@kde.org)
     Copyright (C) 2002 Waldo Bastian (bastian@kde.org)
     Copyright (C) 2006 Samuel Weinig (sam.weinig@gmail.com)
     Copyright (C) 2004, 2005, 2006, 2007 Apple Inc. All rights reserved.
 
     This library is free software; you can redistribute it and/or
     modify it under the terms of the GNU Library General Public
     License as published by the Free Software Foundation; either
@@ skipping 378 matching lines @@
             .toFloat(&m_hasDevicePixelRatioHeaderValue);
     if (!m_hasDevicePixelRatioHeaderValue ||
         m_devicePixelRatioHeaderValue <= 0.0) {
       m_devicePixelRatioHeaderValue = 1.0;
       m_hasDevicePixelRatioHeaderValue = false;
     }
   }
 }
 
 static bool isLoFiImage(const ImageResource& resource) {
-  if (resource.resourceRequest().loFiState() != WebURLRequest::LoFiOn)
+  if (!(resource.resourceRequest().previewsState() &
+        WebURLRequest::ServerLoFiOn)) {
     return false;
+  }
   return !resource.isLoaded() ||
          resource.response()
              .httpHeaderField("chrome-proxy-content-transform")
              .contains("empty-image");
 }
 
 void ImageResource::reloadIfLoFiOrPlaceholderImage(
     ResourceFetcher* fetcher,
     ReloadLoFiOrPlaceholderPolicy policy) {
   if (policy == kReloadIfNeeded && !shouldReloadBrokenPlaceholder())
@@ skipping 91 matching lines @@
 
 const ImageResourceContent* ImageResource::getContent() const {
   return m_content;
 }
 
 ResourcePriority ImageResource::priorityFromObservers() {
   return getContent()->priorityFromObservers();
 }
 
 }  // namespace blink