Move signin status and current user information into AppListModel.

ash/shell/app_list.cc

Index: ash/shell/app_list.cc
diff --git a/ash/shell/app_list.cc b/ash/shell/app_list.cc
index 1fcb9edbebe32e0157488f34d1cd5400039f308c..498de37848faadd64a7adaae4523c5d80ce3a265 100644
--- a/ash/shell/app_list.cc
+++ b/ash/shell/app_list.cc
@@ -298,14 +298,6 @@ class ExampleAppListViewDelegate : public app_list::AppListViewDelegate {
     return gfx::ImageSkia();
   }
 
-  virtual base::string16 GetCurrentUserName() OVERRIDE {
-    return base::string16();
-  }
-
-  virtual base::string16 GetCurrentUserEmail() OVERRIDE {
-    return base::string16();
-  }
-
   virtual void OpenSettings() OVERRIDE {
     // Nothing needs to be done.
   }