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

chrome/browser/loader/chrome_resource_dispatcher_host_delegate.cc

 // 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.
 
 #include "chrome/browser/loader/chrome_resource_dispatcher_host_delegate.h"
 
 #include <stdint.h>
 #include <string>
 #include <utility>
 #include <vector>
@@ skipping 810 matching lines @@
       ResourceRequestInfo::ForRequest(url_request);
   BrowserThread::PostTask(
       BrowserThread::UI, FROM_HERE,
       base::Bind(&NotifyUIThreadOfRequestComplete,
                  info->GetWebContentsGetterForRequest(), url_request->url(),
                  info->GetResourceType(), url_request->was_cached(), net_error,
                  url_request->GetTotalReceivedBytes(),
                  base::TimeTicks::Now() - url_request->creation_time()));
 }
 
-bool ChromeResourceDispatcherHostDelegate::ShouldEnableLoFiMode(
+content::PreviewsState ChromeResourceDispatcherHostDelegate::GetPreviewsState(
     const net::URLRequest& url_request,
     content::ResourceContext* resource_context) {
   ProfileIOData* io_data = ProfileIOData::FromResourceContext(resource_context);
   data_reduction_proxy::DataReductionProxyIOData* data_reduction_proxy_io_data =
       io_data->data_reduction_proxy_io_data();
 
-  if (data_reduction_proxy_io_data)
-    return data_reduction_proxy_io_data->ShouldEnableLoFiMode(url_request);
-  return false;
+  if (data_reduction_proxy_io_data) {
+    return data_reduction_proxy_io_data->ShouldEnableLoFiMode(url_request)
+               ? content::SERVER_LOFI_ON
+               : content::PREVIEWS_OFF;
+  }
+  return content::PREVIEWS_OFF;
 }
 
 // static
 void ChromeResourceDispatcherHostDelegate::
     SetExternalProtocolHandlerDelegateForTesting(
     ExternalProtocolHandler::Delegate* delegate) {
   g_external_protocol_handler_delegate = delegate;
 }
 
 content::NavigationData*
@@ skipping 33 matching lines @@
           base::Bind(&ChromeResourceDispatcherHostDelegate::OnAbortedFrameLoad,
                     base::Unretained(this), url, request_loading_time));
       return;
   }
 
   std::string metric_name = (request_loading_time.InMilliseconds() < 100 ?
       "Net.ErrAborted.Fast" : "Net.ErrAborted.Slow");
   rappor::SampleDomainAndRegistryFromGURL(
       g_browser_process->rappor_service(), metric_name, url);
 }