[Chromecast] Add proxy server support to chromecast

chromecast/browser/cast_browser_main_parts.cc

Index: chromecast/browser/cast_browser_main_parts.cc
diff --git a/chromecast/browser/cast_browser_main_parts.cc b/chromecast/browser/cast_browser_main_parts.cc
index fb1b34a0cb298aeccf35e3fcb15944a1a99c4b81..a616d0e2d34c777ff8cc7f11696f7612b41d13e2 100644
--- a/chromecast/browser/cast_browser_main_parts.cc
+++ b/chromecast/browser/cast_browser_main_parts.cc
@@ -51,6 +51,7 @@
 #include "chromecast/public/cast_sys_info.h"
 #include "chromecast/service/cast_service.h"
 #include "components/prefs/pref_registry_simple.h"
+#include "components/proxy_config/pref_proxy_config_tracker_impl.h"
 #include "content/public/browser/browser_thread.h"
 #include "content/public/browser/child_process_security_policy.h"
 #include "content/public/browser/gpu_data_manager.h"
@@ -425,6 +426,7 @@ int CastBrowserMainParts::PreCreateThreads() {
 void CastBrowserMainParts::PreMainMessageLoopRun() {
   scoped_refptr<PrefRegistrySimple> pref_registry(new PrefRegistrySimple());
   metrics::RegisterPrefs(pref_registry.get());
+  PrefProxyConfigTrackerImpl::RegisterPrefs(pref_registry.get());
   cast_browser_process_->SetPrefService(
       PrefServiceHelper::CreatePrefService(pref_registry.get()));
 
@@ -434,7 +436,9 @@ void CastBrowserMainParts::PreMainMessageLoopRun() {
 
   cast_browser_process_->SetConnectivityChecker(ConnectivityChecker::Create(
       content::BrowserThread::GetTaskRunnerForThread(
-          content::BrowserThread::IO)));
+          content::BrowserThread::IO),
+      cast_browser_process_->pref_proxy_config_tracker()
+          ->CreateTrackingProxyConfigService(nullptr)));
 
   cast_browser_process_->SetNetLog(net_log_.get());