//net changes for stale-while-revalidate

net/http/http_cache_transaction.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 "net/http/http_cache_transaction.h"
 
 #include "build/build_config.h"
 
 #if defined(OS_POSIX)
 #include <unistd.h>
@@ skipping 2101 matching lines @@
   return OK;
 }
 
 int HttpCache::Transaction::BeginCacheValidation() {
   DCHECK(mode_ == READ_WRITE);
 
   ValidationType required_validation = RequiresValidation();
 
   bool skip_validation = (required_validation == VALIDATION_NONE);
 
+  if ((effective_load_flags_ & LOAD_SUPPORT_ASYNC_REVALIDATION) &&
+      required_validation == VALIDATION_ASYNCHRONOUS) {
+    DCHECK(request_->method == "HEAD" || request_->method == "GET");

[hiroshige, 2015/06/12 05:58:03]

The doc says: "Only the GET method is in scope." and //content change allows
only "GET", so should we allow only "GET" here also?

[Adam Rice, 2015/06/12 06:41:57]

You're right. Fixed.

+    skip_validation = true;
+    response_.async_revalidation_required = true;
+  }
+
   if (request_->method == "HEAD" &&
       (truncated_ || response_.headers->response_code() == 206)) {
     DCHECK(!partial_);
     if (skip_validation)
       return SetupEntryForRead();
 
     // Bail out!
     next_state_ = STATE_SEND_REQUEST;
     mode_ = NONE;
     return OK;
@@ skipping 806 matching lines @@
     default:
       NOTREACHED();
   }
 }
 
 void HttpCache::Transaction::OnIOComplete(int result) {
   DoLoop(result);
 }
 
 }  // namespace net