Create a Lite Page bit for previews and fallback to Lo-Fi

third_party/WebKit/public/platform/WebURLRequest.h

 /*
  * Copyright (C) 2009 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 118 matching lines @@
 
   // Used to report performance metrics timed from the UI action that
   // triggered them (as opposed to navigation start time used in the
   // Navigation Timing API).
   enum InputToLoadPerfMetricReportPolicy {
     NoReport,      // Don't report metrics for this WebURLRequest.
     ReportLink,    // Report metrics with UI action link clicked.
     ReportIntent,  // Report metrics with UI action displayed intent.
   };
 
-  // The Previews state which determines whether to request a Preview version of
+  typedef int PreviewsState;
+
+  // The Previews types which determines whether to request a Preview version of
   // the resource.
-  enum PreviewsState {
+  enum PreviewsTypes {
     PreviewsUnspecified = 0,       // Let the browser process decide whether or
                                    // not to request Preview types.
     ServerLoFiOn = 1 << 0,         // Request a Lo-Fi version of the resource
                                    // from the server.
     ClientLoFiOn = 1 << 1,         // Request a Lo-Fi version of the resource
                                    // from the client.
-    PreviewsNoTransform = 1 << 2,  // Explicitly forbid Previews
+    ServerLitePageOn = 1 << 2,     // Request a Lite Page version of the
+                                   // resource from the server.
+    PreviewsNoTransform = 1 << 3,  // Explicitly forbid Previews
                                    // transformations.
-    PreviewsOff = 1 << 3,          // Request a normal (non-Preview) version of
+    PreviewsOff = 1 << 4,          // Request a normal (non-Preview) version of
                                    // the resource. Server transformations may
                                    // still happen if the page is heavy.
     PreviewsStateLast = PreviewsOff
   };
 
   // Indicates which types of ServiceWorkers should skip handling this request.
   enum class SkipServiceWorker {
     // Request can be handled both by a controlling same-origin worker and
     // a cross-origin foreign fetch service worker.
     None,
@@ skipping 192 matching lines @@
   // instance it contains.
   std::unique_ptr<ResourceRequestContainer> m_ownedResourceRequest;
 
   // Should never be null.
   ResourceRequest* m_resourceRequest;
 };
 
 }  // namespace blink
 
 #endif