Make ResourceHandler::OnWillRead able to complete asynchronously.

content/browser/loader/stream_resource_handler.cc

 // Copyright (c) 2013 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 "content/browser/loader/stream_resource_handler.h"
 
 #include "base/bind.h"
 #include "base/logging.h"
 #include "content/browser/loader/resource_controller.h"
 #include "net/url_request/url_request_status.h"
@@ skipping 25 matching lines @@
     std::unique_ptr<ResourceController> controller) {
   controller->Resume();
 }
 
 void StreamResourceHandler::OnWillStart(
     const GURL& url,
     std::unique_ptr<ResourceController> controller) {
   controller->Resume();
 }
 
-bool StreamResourceHandler::OnWillRead(scoped_refptr<net::IOBuffer>* buf,
-                                       int* buf_size) {
+void StreamResourceHandler::OnWillRead(
+    scoped_refptr<net::IOBuffer>* buf,
+    int* buf_size,
+    std::unique_ptr<ResourceController> controller) {
   writer_.OnWillRead(buf, buf_size, -1);
-  return true;
+  controller->Resume();
 }
 
 void StreamResourceHandler::OnReadCompleted(
     int bytes_read,
     std::unique_ptr<ResourceController> controller) {
   writer_.OnReadCompleted(bytes_read,
                           base::Bind(&ResourceController::Resume,
                                      base::Passed(std::move(controller))));
 }
 
 void StreamResourceHandler::OnResponseCompleted(
     const net::URLRequestStatus& status,
     std::unique_ptr<ResourceController> controller) {
   writer_.Finalize(status.error());
   controller->Resume();
 }
 
 void StreamResourceHandler::OnDataDownloaded(int bytes_downloaded) {
   NOTREACHED();
 }
 
 }  // namespace content