Remove stale-while-revalidate experimental implementation.

net/log/net_log_event_type_list.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.
 
 // NOTE: No header guards are used, since this file is intended to be expanded
 // directly into net_log.h. DO NOT include this file anywhere else.
 
 // In the event of a failure, a many end events will have a |net_error|
 // parameter with the integer error code associated with the failure.  Most
 // of these parameters are not individually documented.
@@ skipping 856 matching lines @@
 //     "headers": <The list of header:value pairs>,
 //   }
 EVENT_TYPE(HTTP_CACHE_CALLER_REQUEST_HEADERS)
 
 // Signal a significant change on the flow of the state machine: start again
 // from scratch or create a new network request for byte-range operations.
 // There are no parameters.
 EVENT_TYPE(HTTP_CACHE_RESTART_PARTIAL_REQUEST)
 EVENT_TYPE(HTTP_CACHE_RE_SEND_PARTIAL_REQUEST)
 
-// Identifies the NetLog::Source() for the asynchronous HttpCache::Transaction
-// that will revalidate this entry.
-// The event parameters are:
-//   {
-//      "source_dependency": <Source identifier for the async Transaction>
-//   }
-EVENT_TYPE(HTTP_CACHE_VALIDATE_RESOURCE_ASYNC)
-
-// The start/end of performing an async revalidation.
-// For the BEGIN phase, the event parameters are:
-//   {
-//      "source_dependency": <Source identifier for the Request>
-//      "url": <String of URL being loaded>,
-//      "method": <Method of request>
-//   }
-//
-// For the END phase, if there was an error, the following parameters are
-// attached:
-//   {
-//      "net_error": <Net error code of the failure>,
-//   }
-EVENT_TYPE(ASYNC_REVALIDATION)
-
 // ------------------------------------------------------------------------
 // Disk Cache / Memory Cache
 // ------------------------------------------------------------------------
 
 // The creation/destruction of a disk_cache::EntryImpl object.  The "creation"
 // is considered to be the point at which an Entry is first considered to be
 // good and associated with a key.  Note that disk and memory cache entries
 // share event types.
 //
 // For the BEGIN phase, the following parameters are attached:
@@ skipping 1634 matching lines @@
 //
 // The END phase contains the following parameters:
 //  {
 //    "net_error": <The net_error of the completion of the config request>,
 //    "http_response_code": <The HTTP response code of the config request>,
 //    "failure_count": <The number of consecutive config request failures>,
 //    "retry_delay_seconds": <The length of time after which another config
 //                            request will be made>,
 //  }
 EVENT_TYPE(DATA_REDUCTION_PROXY_CONFIG_REQUEST)