diff -r 000000000000 -r 6474c204b198 browser/devtools/debugger/test/browser_dbg_blackboxing-05.js
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/devtools/debugger/test/browser_dbg_blackboxing-05.js	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,66 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+/**
+ * Test that a "this source is blackboxed" message is shown when necessary
+ * and can be properly dismissed.
+ */
+
+const TAB_URL = EXAMPLE_URL + "doc_binary_search.html";
+
+let gTab, gDebuggee, gPanel, gDebugger;
+let gDeck;
+
+function test() {
+  initDebugger(TAB_URL).then(([aTab, aDebuggee, aPanel]) => {
+    gTab = aTab;
+    gDebuggee = aDebuggee;
+    gPanel = aPanel;
+    gDebugger = gPanel.panelWin;
+    gDeck = gDebugger.document.getElementById("editor-deck");
+
+    waitForSourceShown(gPanel, ".coffee")
+      .then(testSourceEditorShown)
+      .then(toggleBlackBoxing.bind(null, gPanel))
+      .then(testBlackBoxMessageShown)
+      .then(clickStopBlackBoxingButton)
+      .then(testSourceEditorShownAgain)
+      .then(() => closeDebuggerAndFinish(gPanel))
+      .then(null, aError => {
+        ok(false, "Got an error: " + aError.message + "\n" + aError.stack);
+      });
+  });
+}
+
+function testSourceEditorShown() {
+  is(gDeck.selectedIndex, "0",
+    "The first item in the deck should be selected (the source editor).");
+}
+
+function testBlackBoxMessageShown() {
+  is(gDeck.selectedIndex, "1",
+    "The second item in the deck should be selected (the black box message).");
+}
+
+function clickStopBlackBoxingButton() {
+  let finished = waitForThreadEvents(gPanel, "blackboxchange");
+  getEditorBlackboxMessageButton().click();
+  return finished;
+}
+
+function testSourceEditorShownAgain() {
+  is(gDeck.selectedIndex, "0",
+    "The first item in the deck should be selected again (the source editor).");
+}
+
+function getEditorBlackboxMessageButton() {
+  return gDebugger.document.getElementById("black-boxed-message-button");
+}
+
+registerCleanupFunction(function() {
+  gTab = null;
+  gDebuggee = null;
+  gPanel = null;
+  gDebugger = null;
+  gDeck = null;
+});