PART1: Initiated the SignedSettings refactoring.

chrome/browser/chromeos/proxy_cros_settings_provider.h

Index: chrome/browser/chromeos/proxy_cros_settings_provider.h
diff --git a/chrome/browser/chromeos/proxy_cros_settings_provider.h b/chrome/browser/chromeos/proxy_cros_settings_provider.h
index 86801404b56e57580799ea5fbb476466b2140ffc..dab93dd745f8cdbd71ccf96cb8f59b41b4f5b125 100644
--- a/chrome/browser/chromeos/proxy_cros_settings_provider.h
+++ b/chrome/browser/chromeos/proxy_cros_settings_provider.h
@@ -6,6 +6,7 @@
 #define CHROME_BROWSER_CHROMEOS_PROXY_CROS_SETTINGS_PROVIDER_H_
 #pragma once
 
+#include "base/callback.h"
 #include "base/memory/singleton.h"
 #include "base/values.h"
 #include "chrome/browser/chromeos/cros_settings_provider.h"
@@ -16,8 +17,11 @@ namespace chromeos {
 class ProxyCrosSettingsProvider : public CrosSettingsProvider {
  public:
   ProxyCrosSettingsProvider();
+
   // CrosSettingsProvider implementation.
-  virtual bool Get(const std::string& path, Value** out_value) const OVERRIDE;
+  virtual const base::Value* Get(const std::string& path) const OVERRIDE;
+  virtual bool GetTrusted(const std::string& path,
+                          const base::Closure& callback) const OVERRIDE;
   virtual bool HandlesSetting(const std::string& path) const OVERRIDE;
 
   // Set the current network whose proxy settings will be displayed and possibly