PlzNavigate: support the WebRequest API

content/browser/loader/resource_loader.cc

Index: content/browser/loader/resource_loader.cc
diff --git a/content/browser/loader/resource_loader.cc b/content/browser/loader/resource_loader.cc
index 586f22247aeb33c99972112a74ff720050f10930..3bf5d204ee4b333c3cdfc0e84195218e2c9cf3e5 100644
--- a/content/browser/loader/resource_loader.cc
+++ b/content/browser/loader/resource_loader.cc
@@ -482,10 +482,14 @@ void ResourceLoader::StartRequestInternal() {
     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())
+    delegate_->DidStartRequest(this);
 }
 
 void ResourceLoader::CancelRequestInternal(int error, bool from_renderer) {