fix: switch to mojo proxy resolver (3-1-x) (#15813)

atom/browser/net/resolve_proxy_helper.h

@@ -0,0 +1,61 @@
+// Copyright (c) 2018 GitHub, Inc.
+// Use of this source code is governed by the MIT license that can be
+// found in the LICENSE file.
+
+#ifndef ATOM_BROWSER_NET_RESOLVE_PROXY_HELPER_H_
+#define ATOM_BROWSER_NET_RESOLVE_PROXY_HELPER_H_
+
+#include <deque>
+#include <string>
+
+#include "base/memory/ref_counted.h"
+#include "net/proxy_resolution/proxy_service.h"
+#include "url/gurl.h"
+
+namespace net {
+class URLRequestContextGetter;
+}
+
+namespace atom {
+
+class AtomBrowserContext;
+
+class ResolveProxyHelper
+    : public base::RefCountedThreadSafe<ResolveProxyHelper> {
+ public:
+  using ResolveProxyCallback = base::Callback<void(std::string)>;
+
+  explicit ResolveProxyHelper(AtomBrowserContext* browser_context);
+
+  void ResolveProxy(const GURL& url, const ResolveProxyCallback& callback);
+
+ private:
+  friend class base::RefCountedThreadSafe<ResolveProxyHelper>;
+  // A PendingRequest is a resolve request that is in progress, or queued.
+  struct PendingRequest {
+   public:
+    PendingRequest(const GURL& url, const ResolveProxyCallback& callback);
+
+    GURL url;
+    ResolveProxyCallback callback;
+  };
+
+  ~ResolveProxyHelper();
+
+  // Starts the first pending request.
+  void StartPendingRequest();
+  void StartPendingRequestInIO(const GURL& url);
+  void OnProxyResolveComplete(int result);
+  void SendProxyResult(const std::string& proxy);
+
+  net::ProxyInfo proxy_info_;
+  std::deque<PendingRequest> pending_requests_;
+  scoped_refptr<net::URLRequestContextGetter> context_getter_;
+  scoped_refptr<base::SingleThreadTaskRunner> original_thread_;
+
+  DISALLOW_COPY_AND_ASSIGN(ResolveProxyHelper);
+};
+
+}  // namespace atom
+
+#endif  // ATOM_BROWSER_NET_RESOLVE_PROXY_HELPER_H_