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

content/public/browser/resource_dispatcher_host_delegate.h

 // 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.
 
 #ifndef CONTENT_PUBLIC_BROWSER_RESOURCE_DISPATCHER_HOST_DELEGATE_H_
 #define CONTENT_PUBLIC_BROWSER_RESOURCE_DISPATCHER_HOST_DELEGATE_H_
 
 #include <memory>
 #include <string>
 #include <vector>
 
 #include "base/files/file_path.h"
 #include "base/time/time.h"
 #include "content/common/content_export.h"
 #include "content/public/browser/resource_request_info.h"
+#include "content/public/common/previews_state.h"
 #include "content/public/common/resource_type.h"
 #include "ui/base/page_transition_types.h"
 
 class GURL;
 namespace net {
 class AuthChallengeInfo;
 class ClientCertStore;
 class URLRequest;
 }
 
@@ skipping 89 matching lines @@
                                    net::URLRequest* request,
                                    ResourceContext* resource_context,
                                    ResourceResponse* response);
 
   // Notification that a request has completed.
   virtual void RequestComplete(net::URLRequest* url_request, int net_error);
   // Deprecated.
   // TODO(maksims): Remove this once all the callers are modified.
   virtual void RequestComplete(net::URLRequest* url_request);
 
-  // Asks the embedder if Lo-Fi mode should be enabled for the given request. It
-  // is only called for requests with an unspecified Lo-Fi value.
-  virtual bool ShouldEnableLoFiMode(const net::URLRequest& url_request,
-                                    content::ResourceContext* resource_context);
+  // Asks the embedder for the PreviewsState which says which previews should
+  // be enabled for the given request. The PreviewsState is a bitmask of
+  // potentially several Previews optimizations. It is only called for requests
+  // with an unspecified Previews state.
+  virtual PreviewsState GetPreviewsState(
+      const net::URLRequest& url_request,
+      content::ResourceContext* resource_context);
 
   // Asks the embedder for NavigationData related to this request. It is only
   // called for navigation requests.
   virtual NavigationData* GetNavigationData(net::URLRequest* request) const;
 
   // Get platform ClientCertStore. May return nullptr.
   virtual std::unique_ptr<net::ClientCertStore> CreateClientCertStore(
       ResourceContext* resource_context);
 
   // Notification that a main frame load was aborted. The |request_loading_time|
   // parameter contains the time between the load request start and abort.
   // Called on the IO thread.
   virtual void OnAbortedFrameLoad(const GURL& url,
                                   base::TimeDelta request_loading_time);
 
  protected:
   virtual ~ResourceDispatcherHostDelegate();
 };
 
 }  // namespace content
 
 #endif  // CONTENT_PUBLIC_BROWSER_RESOURCE_DISPATCHER_HOST_DELEGATE_H_