diff -r 000000000000 -r 6474c204b198 browser/base/content/test/newtab/browser_newtab_drag_drop.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/base/content/test/newtab/browser_newtab_drag_drop.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,74 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/*
+ * These tests make sure that dragging and dropping sites works as expected.
+ * Sites contained in the grid need to shift around to indicate the result
+ * of the drag-and-drop operation. If the grid is full and we're dragging
+ * a new site into it another one gets pushed out.
+ */
+function runTests() {
+  requestLongerTimeout(2);
+
+  // test a simple drag-and-drop scenario
+  yield setLinks("0,1,2,3,4,5,6,7,8");
+  setPinnedLinks("");
+
+  yield addNewTabPageTab();
+  checkGrid("0,1,2,3,4,5,6,7,8");
+
+  yield simulateDrop(0, 1);
+  checkGrid("1,0p,2,3,4,5,6,7,8");
+
+  // drag a cell to its current cell and make sure it's not pinned afterwards
+  yield setLinks("0,1,2,3,4,5,6,7,8");
+  setPinnedLinks("");
+
+  yield addNewTabPageTab();
+  checkGrid("0,1,2,3,4,5,6,7,8");
+
+  yield simulateDrop(0, 0);
+  checkGrid("0,1,2,3,4,5,6,7,8");
+
+  // ensure that pinned pages aren't moved if that's not necessary
+  yield setLinks("0,1,2,3,4,5,6,7,8");
+  setPinnedLinks(",1,2");
+
+  yield addNewTabPageTab();
+  checkGrid("0,1p,2p,3,4,5,6,7,8");
+
+  yield simulateDrop(0, 3);
+  checkGrid("3,1p,2p,0p,4,5,6,7,8");
+
+  // pinned sites should always be moved around as blocks. if a pinned site is
+  // moved around, neighboring pinned are affected as well
+  yield setLinks("0,1,2,3,4,5,6,7,8");
+  setPinnedLinks("0,1");
+
+  yield addNewTabPageTab();
+  checkGrid("0p,1p,2,3,4,5,6,7,8");
+
+  yield simulateDrop(2, 0);
+  checkGrid("2p,0p,1p,3,4,5,6,7,8");
+
+  // pinned sites should not be pushed out of the grid (unless there are only
+  // pinned ones left on the grid)
+  yield setLinks("0,1,2,3,4,5,6,7,8");
+  setPinnedLinks(",,,,,,,7,8");
+
+  yield addNewTabPageTab();
+  checkGrid("0,1,2,3,4,5,6,7p,8p");
+
+  yield simulateDrop(2, 8);
+  checkGrid("0,1,3,4,5,6,7p,8p,2p");
+
+  // make sure that pinned sites are re-positioned correctly
+  yield setLinks("0,1,2,3,4,5,6,7,8");
+  setPinnedLinks("0,1,2,,,5");
+
+  yield addNewTabPageTab();
+  checkGrid("0p,1p,2p,3,4,5p,6,7,8");
+
+  yield simulateDrop(0, 4);
+  checkGrid("3,1p,2p,4,0p,5p,6,7,8");
+}