Refine the code logic for browser and display engine.

Signed-off-by: Eric Dong <eric.dong@intel.com>
Reviewed-by: Liming Gao <liming.gao@intel.com>



git-svn-id: https://svn.code.sf.net/p/edk2/code/trunk/edk2@14543 6f19259b-4bc3-4df7-8a09-765794883524

MdeModulePkg/Universal/DisplayEngineDxe/FormDisplay.h

@@ -553,6 +553,15 @@ FormDisplay (
   OUT USER_INPUT                *UserInputData
   );
 
+/**
+  Clear Screen to the initial state.
+**/
+VOID
+EFIAPI 
+DriverClearDisplayPage (
+  VOID
+  );
+
 /**
   Exit Display and Clear Screen to the original state.