Offsetting the CellLayout by the remainder space to center it. (Bug 11030678)

Change-Id: Ib83a982498159c21fef5dd8ecc40ac2287d31c60
diff --git a/src/com/android/launcher3/CellLayout.java b/src/com/android/launcher3/CellLayout.java
index 72a6ce2..1d10553 100644
--- a/src/com/android/launcher3/CellLayout.java
+++ b/src/com/android/launcher3/CellLayout.java
@@ -1009,11 +1009,13 @@
 
     @Override
     protected void onLayout(boolean changed, int l, int t, int r, int b) {
+        int offset = getMeasuredWidth() - getPaddingLeft() - getPaddingRight() -
+                (mCountX * mCellWidth);
+        int left = getPaddingLeft() + (int) Math.ceil(offset / 2f);
+        int top = getPaddingTop();
         int count = getChildCount();
         for (int i = 0; i < count; i++) {
             View child = getChildAt(i);
-            int left = getPaddingLeft();
-            int top = getPaddingTop();
             child.layout(left, top,
                     left + r - l,
                     top + b - t);