redesign and reimplement proxy config service and tracker, revise proxy ui on cros

chrome/browser/chromeos/proxy_config_service.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 CHROME_BROWSER_CHROMEOS_PROXY_CONFIG_SERVICE_H_
 #define CHROME_BROWSER_CHROMEOS_PROXY_CONFIG_SERVICE_H_
 #pragma once
 
 #include "chrome/browser/chromeos/proxy_config_service_impl.h"
 
+class PrefProxyConfigTracker;
+
 namespace chromeos {
 
 // Wrapper class for the RefCountedThreadSafe chromeos::ProxyConfigServiceImpl
-// that forwards net::ProxyConfigService interface to the actual implementation,
+// that forwards net::ProxyConfigService interface and extra functionalities
+// to the actual implementation,
 // instantiated in ProfileIOData::CreateProxyConfigService.
-class ProxyConfigService : public net::ProxyConfigService {
+class ProxyConfigService : public net::ProxyConfigService,
+                           public PrefProxyConfigTracker::Observer {

[Mattias Nissler (ping if slow), 2011/10/07 13:32:10]

As I mentioned in the email: Why do we handle the pref observing here only to
pass changes on to ProxyConfigServiceImpl? That seems quite convoluted. Can't we
just extract the pref observing and reading out of PrefProxyConfigTracker into
some base class (say ProxyPrefs) and make ProxyConfigServiceImpl use ProxyPrefs
directly?

[kuan, 2011/10/18 16:25:35]

Done.

  public:
-  explicit ProxyConfigService(
-      const scoped_refptr<ProxyConfigServiceImpl>& impl);
+  ProxyConfigService(const scoped_refptr<ProxyConfigServiceImpl>& impl,
+                     PrefProxyConfigTracker* pref_config_tracker);
   virtual ~ProxyConfigService();
 
   // ProxyConfigService methods.  Called from IO thread.
-  virtual void AddObserver(Observer* observer);
-  virtual void RemoveObserver(Observer* observer);
+  virtual void AddObserver(net::ProxyConfigService::Observer* observer);
+  virtual void RemoveObserver(net::ProxyConfigService::Observer* observer);
   virtual ConfigAvailability GetLatestProxyConfig(net::ProxyConfig* config);
 
+  // PrefProxyConfigTracker::Observer implementation.
+  void OnPrefProxyConfigChanged();
+
  private:
+  void RegisterTracker();
+
   scoped_refptr<ProxyConfigServiceImpl> impl_;
 
+  scoped_refptr<PrefProxyConfigTracker> pref_config_tracker_;
+
+  // Indicates if we've registered for pref_config_tracker_.
+  bool registered_tracker_;
+
   DISALLOW_COPY_AND_ASSIGN(ProxyConfigService);
 };
 
 }  // namespace chromeos
 
 #endif  // CHROME_BROWSER_CHROMEOS_PROXY_CONFIG_SERVICE_H_