add missing APIs related to scrolling

src/api-impl/android/view/View.java

@@ -1291,6 +1291,7 @@ public class View extends Object {
 	}
 
 	public void addOnLayoutChangeListener(OnLayoutChangeListener listener) {}
+	public void removeOnLayoutChangeListener(OnLayoutChangeListener listener) {}
 
 	public boolean isSelected() {return false;}
 
@@ -1560,4 +1561,12 @@ public class View extends Object {
 	protected int computeHorizontalScrollExtent() {
 		return getWidth();
 	}
+
+	protected int computeVerticalScrollRange() {
+		return getHeight();
+	}
+
+	protected int computeVerticalScrollExtent() {
+		return getHeight();
+	}
 }