Refactor ViewsDelegate singleton

ui/views/views_delegate.h

Index: ui/views/views_delegate.h
diff --git a/ui/views/views_delegate.h b/ui/views/views_delegate.h
index 39c7f5a54ea7186b1172a2f84bb16a6c72dd5bd3..119f1c839876ea05a6f93631993933dc85a44aef 100644
--- a/ui/views/views_delegate.h
+++ b/ui/views/views_delegate.h
@@ -60,6 +60,7 @@ class NativeWidgetDelegate;
 // framework. It is used to obtain various high level application utilities
 // and perform some actions such as window placement saving.
 //
+// XXX

[sadrul, 2015/06/08 03:27:43]

?

[mohsen, 2015/06/08 19:27:34]

Sorry! This was here to remind me to update the comment, and... it didn't! Done.

 // The embedding app must set views_delegate to assign its ViewsDelegate
 // implementation.
 class VIEWS_EXPORT ViewsDelegate {
@@ -73,9 +74,10 @@ class VIEWS_EXPORT ViewsDelegate {
   };
 #endif
 
-  ViewsDelegate();
   virtual ~ViewsDelegate();
 
+  static ViewsDelegate* GetInstance();

[sadrul, 2015/06/08 03:27:43]

Clarify here that GetInstance() can return null if an instance hasn't been
created yet.

[mohsen, 2015/06/08 19:27:34]

Done.

+
   // Saves the position, size and "show" state for the window with the
   // specified name.
   virtual void SaveWindowPlacement(const Widget* widget,
@@ -160,8 +162,8 @@ class VIEWS_EXPORT ViewsDelegate {
   // Returns a blocking pool task runner given a TaskRunnerType.
   virtual scoped_refptr<base::TaskRunner> GetBlockingPoolTaskRunner();
 
-  // The active ViewsDelegate used by the views system.
-  static ViewsDelegate* views_delegate;
+ protected:
+  ViewsDelegate();
 
  private:
   scoped_ptr<ViewsTouchEditingControllerFactory> views_tsc_factory_;