AU: Make proxy resolution asynchronous.

chrome_proxy_resolver.h

 // Copyright (c) 2010 The Chromium OS 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 CHROMEOS_PLATFORM_UPDATE_ENGINE_CHROME_PROXY_RESOLVER_H__
 #define CHROMEOS_PLATFORM_UPDATE_ENGINE_CHROME_PROXY_RESOLVER_H__
 
 #include <deque>
 #include <string>
 
 #include <curl/curl.h>
 #include <gtest/gtest_prod.h>  // for FRIEND_TEST
 
 #include "update_engine/dbus_interface.h"
 #include "update_engine/proxy_resolver.h"
 
 namespace chromeos_update_engine {
 
 extern const char kSessionManagerService[];
 extern const char kSessionManagerPath[];
 extern const char kSessionManagerInterface[];
 extern const char kSessionManagerRetrievePropertyMethod[];
 extern const char kSessionManagerProxySettingsKey[];
 
 // Class to resolve proxy for a url based on Chrome's proxy settings.
 
 // Currently only supports manual settings, not PAC files or autodetected
 // settings.
 
+struct ChromeProxyResolverClosureArgs {
+  std::string url;
+  ProxiesResolvedFn callback;
+  void* data;
+};
+
 class ChromeProxyResolver : public ProxyResolver {
  public:
   explicit ChromeProxyResolver(DbusGlibInterface* dbus) : dbus_(dbus) {}
   virtual ~ChromeProxyResolver() {}
 
   virtual bool GetProxiesForUrl(const std::string& url,
-                                std::deque<std::string>* out_proxies);
+                                ProxiesResolvedFn callback,
+                                void* data);
 
   // Get the curl proxy type for a given proxy url. Returns true on success.
   // Note: if proxy is kNoProxy, this will return false.
   static bool GetProxyType(const std::string& proxy, curl_proxytype* out_type);
 
  private:
   FRIEND_TEST(ChromeProxyResolverTest, GetProxiesForUrlWithSettingsTest);
 
+  // Closure callback, so we can pretend we need to wait on the main loop
+  // before returing proxies to the client.
+  void GetProxiesForUrlCallback(ChromeProxyResolverClosureArgs args);
+
   // Fetches a dbus proxy to session manager. Returns NULL on failure.
   DBusGProxy* DbusProxy();
 
   // Fetches the json-encoded proxy settings string from the session manager.
   bool GetJsonProxySettings(DBusGProxy* proxy, std::string* out_json);
 
   // Given a |url| and the json encoded settings |json_settings|,
   // returns the proper proxy servers in |out_proxies|. Returns true on
   // success.
   bool GetProxiesForUrlWithSettings(const std::string& url,
                                     const std::string& json_settings,
                                     std::deque<std::string>* out_proxies);
 
   DbusGlibInterface* dbus_;
   
   DISALLOW_COPY_AND_ASSIGN(ChromeProxyResolver);
 };
 
 }  // namespace chromeos_update_engine
 
 #endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_CHROME_PROXY_RESOLVER_H__