Improve performance of proxy resolver by tracing DNS dependencies.

net/proxy/proxy_resolver_js_bindings.h

-// Copyright (c) 2011 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 NET_PROXY_PROXY_RESOLVER_JS_BINDINGS_H_
-#define NET_PROXY_PROXY_RESOLVER_JS_BINDINGS_H_
-
-#include <string>
-
-#include "base/string16.h"
-#include "net/base/net_export.h"
-
-namespace net {
-
-class HostResolver;
-class NetLog;
-class ProxyResolverErrorObserver;
-struct ProxyResolverRequestContext;
-class SyncHostResolver;
-
-// Interface for the javascript bindings.
-class NET_EXPORT_PRIVATE ProxyResolverJSBindings {
- public:
-  ProxyResolverJSBindings() : current_request_context_(NULL) {}
-
-  virtual ~ProxyResolverJSBindings() {}
-
-  // Handler for "alert(message)"
-  virtual void Alert(const string16& message) = 0;
-
-  // Handler for "myIpAddress()". Returns true on success and fills
-  // |*first_ip_address| with the result.
-  virtual bool MyIpAddress(std::string* first_ip_address) = 0;
-
-  // Handler for "myIpAddressEx()". Returns true on success and fills
-  // |*ip_address_list| with the result.
-  //
-  // This is a Microsoft extension to PAC for IPv6, see:
-  // http://blogs.msdn.com/b/wndp/archive/2006/07/13/ipv6-pac-extensions-v0-9.aspx
-
-  virtual bool MyIpAddressEx(std::string* ip_address_list) = 0;
-
-  // Handler for "dnsResolve(host)". Returns true on success and fills
-  // |*first_ip_address| with the result.
-  virtual bool DnsResolve(const std::string& host,
-                          std::string* first_ip_address) = 0;
-
-  // Handler for "dnsResolveEx(host)". Returns true on success and fills
-  // |*ip_address_list| with the result.
-  //
-  // This is a Microsoft extension to PAC for IPv6, see:
-  // http://blogs.msdn.com/b/wndp/archive/2006/07/13/ipv6-pac-extensions-v0-9.aspx
-  virtual bool DnsResolveEx(const std::string& host,
-                            std::string* ip_address_list) = 0;
-
-  // Handler for when an error is encountered. |line_number| may be -1
-  // if a line number is not applicable to this error.
-  virtual void OnError(int line_number, const string16& error) = 0;
-
-  // Called before the thread running the proxy resolver is stopped.
-  virtual void Shutdown() = 0;
-
-  // Creates a default javascript bindings implementation that will:
-  //   - Send script error messages to both VLOG(1) and the NetLog.
-  //   - Send script alert()s to both VLOG(1) and the NetLog.
-  //   - Use the provided host resolver to service dnsResolve().
-  //
-  // Takes ownership of |host_resolver| and |error_observer| (the latter can
-  // be NULL).
-  static ProxyResolverJSBindings* CreateDefault(
-      SyncHostResolver* host_resolver,
-      NetLog* net_log,
-      ProxyResolverErrorObserver* error_observer);
-
-  // Sets details about the currently executing FindProxyForURL() request.
-  void set_current_request_context(
-      ProxyResolverRequestContext* current_request_context) {
-    current_request_context_ = current_request_context;
-  }
-
-  // Retrieves details about the currently executing FindProxyForURL() request.
-  ProxyResolverRequestContext* current_request_context() {
-    return current_request_context_;
-  }
-
- private:
-  ProxyResolverRequestContext* current_request_context_;
-};
-
-}  // namespace net
-
-#endif  // NET_PROXY_PROXY_RESOLVER_JS_BINDINGS_H_