Allow hostnames in socket.connect().

chrome/browser/extensions/api/dns/host_resolver_wrapper.h

+// 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.
+
+#ifndef CHROME_BROWSER_EXTENSIONS_API_DNS_HOST_RESOLVER_WRAPPER_H_
+#define CHROME_BROWSER_EXTENSIONS_API_DNS_HOST_RESOLVER_WRAPPER_H_
+#pragma once
+
+#include "base/memory/singleton.h"
+#include "net/base/host_resolver.h"
+
+namespace extensions {
+
+// Used for testing. In production code, this class does nothing interesting.
+// This class is a singleton that holds a pointer to a mock HostResolver, or
+// else to NULL. API classes that need to resolve hostnames ask this class for
+// the correct HostResolver to use, passing in the one that they want to use,
+// thereby avoiding most lifetime issues, and it will reply with either that
+// same one, or else the test version to use instead.
+//
+// This is a pretty complicated way to replace a single pointer with another.
+// TODO(miket): make the previous statement obsolete.
+class HostResolverWrapper {
+ public:
+  static HostResolverWrapper* GetInstance();
+
+  // Given a pointer to a real host resolver, returns the same pointer or else
+  // a substitute MockHostResolver to use instead. If
+  // SetHostResolverForTesting() hasn't been called, then this method returns
+  // the supplied argument as its result.
+  net::HostResolver* GetHostResolver(net::HostResolver* real_resolver);
+
+  // Sets the MockHostResolver to return in GetHostResolver().
+  void SetHostResolverForTesting(net::HostResolver* mock_resolver);
+
+ private:
+  HostResolverWrapper();
+  friend struct DefaultSingletonTraits<HostResolverWrapper>;
+
+  net::HostResolver* resolver_;
+
+  DISALLOW_COPY_AND_ASSIGN(HostResolverWrapper);
+};
+
+}  // namespace extensions
+
+#endif  // CHROME_BROWSER_EXTENSIONS_API_DNS_HOST_RESOLVER_WRAPPER_H_