Check current index in PieStackView

    Bug: 5569079

Change-Id: I5af1e37c1a73dcf94ae684ac5f2796db5a4ab3be
diff --git a/src/com/android/browser/view/PieStackView.java b/src/com/android/browser/view/PieStackView.java
index ca641f9..7e1922d 100644
--- a/src/com/android/browser/view/PieStackView.java
+++ b/src/com/android/browser/view/PieStackView.java
@@ -84,7 +84,7 @@
 
     @Override
     public void draw(Canvas canvas) {
-        if (mViews != null) {
+        if ((mViews != null) && (mCurrent > -1)) {
             final int n = mViews.size();
             for (int i = 0; i < mCurrent; i++) {
                 drawView(mViews.get(i), canvas);