Plumb network stack information about existence of cached copy

content/common/resource_messages.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.
 
 // IPC messages for resource loading.
 //
 // NOTE: All messages must send an |int request_id| as their first parameter.
 
 // Multiply-included message file, hence no include guard.
 #include "base/memory/shared_memory.h"
@@ skipping 253 matching lines @@
 
 // Sent when some data from a resource request has been downloaded to
 // file. This is only called in the 'download_to_file' case and replaces
 // ResourceMsg_DataReceived in the call sequence in that case.
 IPC_MESSAGE_CONTROL3(ResourceMsg_DataDownloaded,
                      int /* request_id */,
                      int /* data_len */,
                      int /* encoded_data_length */)
 
 // Sent when the request has been completed.
-IPC_MESSAGE_CONTROL5(ResourceMsg_RequestComplete,
+IPC_MESSAGE_CONTROL6(ResourceMsg_RequestComplete,
                      int /* request_id */,
                      int /* error_code */,
                      bool /* was_ignored_by_handler */,
+                     bool /* stale_copy_in_cache */,
                      std::string /* security info */,
                      base::TimeTicks /* completion_time */)
 
 // Resource messages sent from the renderer to the browser.
 
 // Makes a resource request via the browser.
 IPC_MESSAGE_ROUTED2(ResourceHostMsg_RequestResource,
                     int /* request_id */,
                     ResourceHostMsg_Request)
 
@@ skipping 29 matching lines @@
                      int /* request_id */)
 
 // Sent when the renderer process deletes a resource loader.
 IPC_MESSAGE_CONTROL1(ResourceHostMsg_ReleaseDownloadedFile,
                      int /* request_id */)
 
 // Sent by the renderer when a resource request changes priority.
 IPC_MESSAGE_CONTROL2(ResourceHostMsg_DidChangePriority,
                      int /* request_id */,
                      net::RequestPriority)