Reclassify heapsnapshot and nsJSInspector as not part of devtools

This resolves Issue #316

dom/heapsnapshot/tests/unit/test_HeapSnapshot_takeCensus_04.js

@@ -0,0 +1,36 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test that HeapSnapshot.prototype.takeCensus finds GC roots that are on the
+// stack.
+//
+// Ported from js/src/jit-test/tests/debug/Memory-takeCensus-04.js
+
+function run_test() {
+  var g = newGlobal();
+  var dbg = new Debugger(g);
+
+  g.eval(`
+function withAllocationMarkerOnStack(f) {
+  (function () {
+    var onStack = allocationMarker();
+    f();
+  }());
+}
+`);
+
+  equal("AllocationMarker" in saveHeapSnapshotAndTakeCensus(dbg).objects, false,
+        "There shouldn't exist any allocation markers in the census.");
+
+  var allocationMarkerCount;
+  g.withAllocationMarkerOnStack(() => {
+    const census = saveHeapSnapshotAndTakeCensus(dbg);
+    allocationMarkerCount = census.objects.AllocationMarker.count;
+  });
+
+  equal(allocationMarkerCount, 1,
+        "Should have one allocation marker in the census, because there " +
+        "was one on the stack.");
+
+  do_test_finished();
+}