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

chrome/browser/chromeos/proxy_config_service.cc

 // 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.
 
 #include "chrome/browser/chromeos/proxy_config_service.h"
 
+#include "chrome/browser/net/pref_proxy_config_service.h"
+
 namespace chromeos {
 
 ProxyConfigService::ProxyConfigService(
-    const scoped_refptr<ProxyConfigServiceImpl>& impl)
-    : impl_(impl) {
+    const scoped_refptr<ProxyConfigServiceImpl>& impl,
+    PrefProxyConfigTracker* pref_config_tracker)
+    : impl_(impl),
+      pref_config_tracker_(pref_config_tracker) {
 }
 
-ProxyConfigService::~ProxyConfigService() {}
-
-void ProxyConfigService::AddObserver(Observer* observer) {
-  impl_->AddObserver(observer);
+ProxyConfigService::~ProxyConfigService() {
+  if (registered_tracker_)
+    pref_config_tracker_->RemoveObserver(this);
 }
 
-void ProxyConfigService::RemoveObserver(Observer* observer) {
+void ProxyConfigService::AddObserver(
+    net::ProxyConfigService::Observer* observer) {
+  impl_->AddObserver(observer);
+  RegisterTracker();
+}
+
+void ProxyConfigService::RemoveObserver(
+    net::ProxyConfigService::Observer* observer) {
   impl_->RemoveObserver(observer);
 }
 
 ProxyConfigService::ConfigAvailability ProxyConfigService::GetLatestProxyConfig(
     net::ProxyConfig* config) {
+  RegisterTracker();
   return impl_->IOGetProxyConfig(config);
 }
 
+void ProxyConfigService::OnPrefProxyConfigChanged() {
+  impl_->OnPrefProxyConfigChanged(pref_config_tracker_);
+}
+
+void ProxyConfigService::RegisterTracker() {
+  if (!registered_tracker_) {
+    pref_config_tracker_->AddObserver(this);
+    registered_tracker_ = true;
+  }
+}
+
 }  // namespace chromeos