wip 3029324: Implement new drag feedback

- Show page borders when dragging
- Enlarge scroll region (landscape only)
- When inside scroll region, show green border on adjacent page
diff --git a/src/com/android/launcher2/Launcher.java b/src/com/android/launcher2/Launcher.java
index c065170..f5a5935 100644
--- a/src/com/android/launcher2/Launcher.java
+++ b/src/com/android/launcher2/Launcher.java
@@ -2029,7 +2029,7 @@
             final Canvas c = new Canvas(bitmap);
             c.scale(scale, scale);
             c.translate(-cell.getLeftPadding(), -cell.getTopPadding());
-            cell.dispatchDraw(c);
+            cell.drawChildren(c);
 
             image.setBackgroundDrawable(resources.getDrawable(R.drawable.preview_background));
             image.setImageBitmap(bitmap);