Fix DCHECK failure when Manifest fetch has an Access Control error.

content/renderer/fetchers/web_url_loader_client_impl.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 "content/renderer/fetchers/web_url_loader_client_impl.h"
 
 #include "base/logging.h"
 #include "third_party/WebKit/public/platform/WebURLError.h"
 #include "third_party/WebKit/public/platform/WebURLLoader.h"
 #include "third_party/WebKit/public/platform/WebURLResponse.h"
@@ skipping 12 matching lines @@
     blink::WebURLLoader* loader, const blink::WebURLResponse& response) {
   DCHECK(!completed_);
   response_ = response;
 }
 
 void WebURLLoaderClientImpl::didReceiveData(
     blink::WebURLLoader* loader,
     const char* data,
     int data_length,
     int encoded_data_length) {
-  DCHECK(!completed_);
+  // The AssociatedURLLoader will continue after a load failure.
+  // For example, for an Access Control error.
+  if (completed_)
+    return;
   DCHECK(data_length > 0);
 
   data_.append(data, data_length);
 }
 
 void WebURLLoaderClientImpl::didReceiveCachedMetadata(
     blink::WebURLLoader* loader,
     const char* data,
     int data_length) {
   DCHECK(!completed_);
   DCHECK(data_length > 0);
 
   metadata_.assign(data, data_length);
 }
 
 void WebURLLoaderClientImpl::didFinishLoading(
     blink::WebURLLoader* loader,
     double finishTime,
     int64_t total_encoded_data_length) {
+  // The AssociatedURLLoader will continue after a load failure.
+  // For example, for an Access Control error.
+  if (completed_)
+    return;
   OnLoadCompleteInternal(LOAD_SUCCEEDED);
 }
 
 void WebURLLoaderClientImpl::didFail(blink::WebURLLoader* loader,
                                      const blink::WebURLError& error) {
   OnLoadCompleteInternal(LOAD_FAILED);
 }
 
 void WebURLLoaderClientImpl::Cancel() {
   OnLoadCompleteInternal(LOAD_FAILED);
 }
 
 void WebURLLoaderClientImpl::OnLoadCompleteInternal(LoadStatus status) {
   DCHECK(!completed_);
   DCHECK(status_ == LOADING);
 
   completed_ = true;
   status_ = status;
 
   OnLoadComplete();
 }
 
 }  // namespace content