Make CrOS proxy configuration write prefs directly.

chrome/test/testing_profile.cc

Index: chrome/test/testing_profile.cc
diff --git a/chrome/test/testing_profile.cc b/chrome/test/testing_profile.cc
index 8e4a009b558d849cd8f37dd7ea85a2cf22455c0e..0f6a27c21f00ccf09181c87beed8cc16dfc69f8f 100644
--- a/chrome/test/testing_profile.cc
+++ b/chrome/test/testing_profile.cc
@@ -14,6 +14,7 @@
 #include "base/string_number_conversions.h"
 #include "chrome/browser/autocomplete/autocomplete_classifier.h"
 #include "chrome/browser/bookmarks/bookmark_model.h"
+#include "chrome/browser/browser_process.h"
 #include "chrome/browser/browser_thread.h"
 #include "chrome/browser/content_settings/host_content_settings_map.h"
 #include "chrome/browser/dom_ui/ntp_resource_cache.h"
@@ -703,8 +704,11 @@ void TestingProfile::set_last_selected_directory(const FilePath& path) {
 }
 
 PrefProxyConfigTracker* TestingProfile::GetProxyConfigTracker() {
-  if (!pref_proxy_config_tracker_)
-    pref_proxy_config_tracker_ = new PrefProxyConfigTracker(GetPrefs());
+  if (!pref_proxy_config_tracker_) {
+    pref_proxy_config_tracker_ =
+        new PrefProxyConfigTracker(GetPrefs(),
+                                   g_browser_process->local_state());
+  }
 
   return pref_proxy_config_tracker_;
 }