ash: Constantify user methods of SystemTrayDelegate.

ash/shell.cc

Index: ash/shell.cc
diff --git a/ash/shell.cc b/ash/shell.cc
index 913d585baf1fa8a4c42c2ddf6ce2a464f11e4538..fd8c85b355cc91078538ea9a9d491429ea252aa2 100644
--- a/ash/shell.cc
+++ b/ash/shell.cc
@@ -192,20 +192,20 @@ class DummySystemTrayDelegate : public SystemTrayDelegate {
 
  private:
 
-  // SystemTrayDelegate implementation.
-  virtual const std::string GetUserDisplayName() OVERRIDE {
+  // Overridden from SystemTrayDelegate:
+  virtual const std::string GetUserDisplayName() const OVERRIDE {
     return "chronos";
   }
 
-  virtual const std::string GetUserEmail() OVERRIDE {
+  virtual const std::string GetUserEmail() const OVERRIDE {
     return "chr@nos";
   }
 
-  virtual const SkBitmap& GetUserImage() OVERRIDE {
+  virtual const SkBitmap& GetUserImage() const OVERRIDE {
     return null_image_;
   }
 
-  virtual user::LoginStatus GetUserLoginStatus() OVERRIDE {
+  virtual user::LoginStatus GetUserLoginStatus() const OVERRIDE {
     return user::LOGGED_IN_USER;
   }