Reclassify heapsnapshot and nsJSInspector as not part of devtools

This resolves Issue #316

dom/heapsnapshot/tests/unit/test_HeapAnalyses_readHeapSnapshot_01.js

@@ -0,0 +1,18 @@
+/* Any copyright is dedicated to the Public Domain.
+   http://creativecommons.org/publicdomain/zero/1.0/ */
+
+// Test that the HeapAnalyses{Client,Worker} can read heap snapshots.
+
+function run_test() {
+  run_next_test();
+}
+
+add_task(function* () {
+  const client = new HeapAnalysesClient();
+
+  const snapshotFilePath = saveNewHeapSnapshot();
+  yield client.readHeapSnapshot(snapshotFilePath);
+  ok(true, "Should have read the heap snapshot");
+
+  client.destroy();
+});