PlzNavigate: support the WebRequest API

content/browser/loader/resource_loader.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/browser/loader/resource_loader.h"
 
 #include <utility>
 
 #include "base/command_line.h"
 #include "base/location.h"
@@ skipping 464 matching lines @@
   CancelRequest(false);
 }
 
 void ResourceLoader::StartRequestInternal() {
   DCHECK(!request_->is_pending());
 
   if (!request_->status().is_success()) {
     return;
   }
 
+  base::WeakPtr<ResourceLoader> weak_self = weak_ptr_factory_.GetWeakPtr();
   started_request_ = true;
   request_->Start();
 
-  delegate_->DidStartRequest(this);
+  // Starting the request may have lead to the deletion of this ResourceLoader
+  // if an error occured when calling NetworkDelegate::NotifyBeforeURLRequest.
+  if (weak_self.get())

[nasko, 2016/09/22 18:32:50]

This seems like a generic issue unrelated to the goal of the CL, right? If so,
can we land it separately?

[clamy, 2016/09/26 15:37:51]

Done.

+    delegate_->DidStartRequest(this);
 }
 
 void ResourceLoader::CancelRequestInternal(int error, bool from_renderer) {
   DVLOG(1) << "CancelRequestInternal: " << request_->url().spec();
 
   ResourceRequestInfoImpl* info = GetRequestInfo();
 
   // WebKit will send us a cancel for downloads since it no longer handles
   // them.  In this case, ignore the cancel since we handle downloads in the
   // browser.
@@ skipping 218 matching lines @@
     }
 
     UMA_HISTOGRAM_ENUMERATION("Net.Prefetch.Pattern", status, STATUS_MAX);
   } else if (request_->response_info().unused_since_prefetch) {
     TimeDelta total_time = base::TimeTicks::Now() - request_->creation_time();
     UMA_HISTOGRAM_TIMES("Net.Prefetch.TimeSpentOnPrefetchHit", total_time);
   }
 }
 
 }  // namespace content