Missing updatestats (#351)

* aligning screeninit with pxt32

* remove shim

* missing shim

* missing shim

libs/core/screen.cpp

@@ -63,6 +63,11 @@ void updateScreen(Image img) {
     }
 }
 
+//%
+void updateStats(String str) {
+
+}
+
 void screen_init() {
     DMESG("init screen");
     if (mappedFrameBuffer)

libs/screen/targetoverrides.ts

@@ -5,25 +5,21 @@
 //% groups=["0.,","1#*"]
 function img(lits: any, ...args: any[]): Image { return null }
 
-
 let screen = image.create(DAL.LCD_WIDTH, DAL.LCD_HEIGHT)
 
 namespace _screen_internal {
     //% shim=pxt::updateScreen
     function updateScreen(img: Image): void {}
+    //% shim=pxt::updateStats
+    function updateStats(msg: string): void {}
 
-    control.addFrameHandler(200, () => {
-        updateScreen(screen)
-    })
-
-    updateScreen(screen)
+    control.setupScreenRefresh(() => updateScreen(screen))
 
     export function _stats(msg: string) {
-        // show the msg somewhere - it contains frame rate etc
+        updateStats(msg)
     }
 }
 
-
 namespace brick {
     export const LINE_HEIGHT = 12;