Clean up dns prefetch code, and also port it.

chrome/browser/browser_prefs.cc

Index: chrome/browser/browser_prefs.cc
diff --git a/chrome/browser/browser_prefs.cc b/chrome/browser/browser_prefs.cc
index fb39796bf5416a9aba65238f62f45146e9e52679..74aea18469d55d67a5c162a244117ae42a9b3f90 100644
--- a/chrome/browser/browser_prefs.cc
+++ b/chrome/browser/browser_prefs.cc
@@ -9,6 +9,7 @@
 #include "chrome/browser/browser_shutdown.h"
 #include "chrome/browser/cache_manager_host.h"
 #include "chrome/browser/metrics/metrics_service.h"
+#include "chrome/browser/net/dns_global.h"
 #include "chrome/browser/password_manager/password_manager.h"
 #include "chrome/browser/renderer_host/browser_render_process_host.h"
 #include "chrome/browser/search_engines/template_url_prepopulate_data.h"
@@ -17,7 +18,6 @@
 #include "chrome/browser/tab_contents/web_contents.h"
 
 #if defined(OS_WIN)  // TODO(port): whittle this down as we port
-#include "chrome/browser/net/dns_global.h"
 #include "chrome/browser/download/download_manager.h"
 #include "chrome/browser/external_protocol_handler.h"
 #include "chrome/browser/safe_browsing/safe_browsing_service.h"
@@ -44,10 +44,10 @@ void RegisterAllPrefs(PrefService* user_prefs, PrefService* local_state) {
   MetricsLog::RegisterPrefs(local_state);
   MetricsService::RegisterPrefs(local_state);
   browser_shutdown::RegisterPrefs(local_state);
+  chrome_browser_net::RegisterPrefs(local_state);
 #if defined(OS_WIN)  // TODO(port): whittle this down as we port
   BookmarkManagerView::RegisterPrefs(local_state);
   BrowserView::RegisterBrowserViewPrefs(local_state);
-  chrome_browser_net::RegisterPrefs(local_state);
   PageInfoWindow::RegisterPrefs(local_state);
   TaskManager::RegisterPrefs(local_state);
   ExternalProtocolHandler::RegisterPrefs(local_state);
@@ -57,10 +57,10 @@ void RegisterAllPrefs(PrefService* user_prefs, PrefService* local_state) {
   SessionStartupPref::RegisterUserPrefs(user_prefs);
   Browser::RegisterUserPrefs(user_prefs);
   PasswordManager::RegisterUserPrefs(user_prefs);
+  chrome_browser_net::RegisterUserPrefs(user_prefs);
 #if defined(OS_WIN)  // TODO(port): whittle this down as we port
   BookmarkBarView::RegisterUserPrefs(user_prefs);
   BookmarkTableView::RegisterUserPrefs(user_prefs);
-  chrome_browser_net::RegisterUserPrefs(user_prefs);
   DownloadManager::RegisterUserPrefs(user_prefs);
   SSLManager::RegisterUserPrefs(user_prefs);
 #endif