Fix for 593676 - Minimizes/eliminates momentary flash of Windows frame

ui/views/win/hwnd_message_handler.h

Index: ui/views/win/hwnd_message_handler.h
diff --git a/ui/views/win/hwnd_message_handler.h b/ui/views/win/hwnd_message_handler.h
index bf25d11eb77e245539acacd836bcfca7fa3c792c..a04bfa780b2ec6531d255977adca018e61f4f88e 100644
--- a/ui/views/win/hwnd_message_handler.h
+++ b/ui/views/win/hwnd_message_handler.h
@@ -211,6 +211,7 @@ class VIEWS_EXPORT HWNDMessageHandler :
 
  private:
   typedef std::set<DWORD> TouchIDs;
+  enum class DwmFrameState { OFF, ON };
 
   // Overridden from WindowImpl:
   HICON GetDefaultWindowIcon() const override;
@@ -314,6 +315,10 @@ class VIEWS_EXPORT HWNDMessageHandler :
 
   bool HasSystemFrame() const;
 
+  // Adds or removes the frame extension into client area with
+  // DwmExtendFrameIntoClientArea.
+  void SetDwmFrameExtension(DwmFrameState state);
+
   // Message Handlers ----------------------------------------------------------
 
   BEGIN_SAFE_MSG_MAP_EX(weak_factory_)