NetworkService: Destroy URLLoaders when a NetworkContext is destroyed.

content/network/network_context.h

 // Copyright 2017 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.
 
 #ifndef CONTENT_NETWORK_NETWORK_CONTEXT_H_
 #define CONTENT_NETWORK_NETWORK_CONTEXT_H_
 
 #include <stdint.h>
 
 #include <memory>
@@ skipping 44 matching lines @@
   // Put it below |url_request_context_| so that it outlives all the
   // NetworkServiceURLLoaderFactoryImpl instances.
   mojo::StrongBindingSet<mojom::URLLoaderFactory> loader_factory_bindings_;
 
   // URLLoaderImpls register themselves with the NetworkContext so that they can
   // be cleaned up when the NetworkContext goes away. This is needed as
   // net::URLRequests held by URLLoaderImpls have to be gone when
   // net::URLRequestContext (held by NetworkContext) is destroyed.
   std::set<URLLoaderImpl*> url_loaders_;
 
-  // Set when entering the destructor, in order to avoid manipulations of the
-  // |url_loaders_| (as a url_loader might delete itself in Cleanup()).
-  bool in_shutdown_;
-
   mojom::NetworkContextParamsPtr params_;
 
   mojo::Binding<mojom::NetworkContext> binding_;
 
   DISALLOW_COPY_AND_ASSIGN(NetworkContext);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_NETWORK_NETWORK_CONTEXT_H_