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>
 
@@ skipping 103 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 Previews State which says which previews should

[nasko, 2016/12/08 22:19:33]

nit: PreviewsState

[megjablon, 2016/12/09 20:35:54]

Done.

+  // be enabled for the given request. It is only called for requests with an
+  // unspecified Previews state of zero.

[nasko, 2016/12/08 22:19:33]

The state is not zero, it has a meaningful name. Zero is the underlying
representation used for it.

[megjablon, 2016/12/09 20:35:54]

Done.

+  virtual int GetPreviewsState(const net::URLRequest& url_request,

[nasko, 2016/12/08 22:19:33]

Why isn't the return value PreviewsState?

[megjablon, 2016/12/09 20:35:55]

Done.

+                               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_