Accounting for background padding when drawing the bg. (Bug 10881814)

Change-Id: I516786c54e1b4b66a601337bd69b8f198dcee2aa
diff --git a/src/com/android/launcher3/CellLayout.java b/src/com/android/launcher3/CellLayout.java
index 1d10553..5c6a694 100644
--- a/src/com/android/launcher3/CellLayout.java
+++ b/src/com/android/launcher3/CellLayout.java
@@ -1025,7 +1025,12 @@
     @Override
     protected void onSizeChanged(int w, int h, int oldw, int oldh) {
         super.onSizeChanged(w, h, oldw, oldh);
-        mBackgroundRect.set(0, 0, w, h);
+
+        // Expand the background drawing bounds by the padding baked into the background drawable
+        Rect padding = new Rect();
+        mNormalBackground.getPadding(padding);
+        mBackgroundRect.set(-padding.left, -padding.top, w + padding.right, h + padding.bottom);
+
         mForegroundRect.set(mForegroundPadding, mForegroundPadding,
                 w - mForegroundPadding, h - mForegroundPadding);
     }