Show map -> transition array -> descriptor array to the heap profiler.

test/cctest/test-heap-profiler.cc

Index: test/cctest/test-heap-profiler.cc
diff --git a/test/cctest/test-heap-profiler.cc b/test/cctest/test-heap-profiler.cc
index 3e03ae96a7694f879a8181d5cc906221219dffc7..1be64d91061ed427d6103f906494adf8c6483956 100644
--- a/test/cctest/test-heap-profiler.cc
+++ b/test/cctest/test-heap-profiler.cc
@@ -1658,3 +1658,25 @@ TEST(NoRefsToNonEssentialEntries) {
       GetProperty(global_object, v8::HeapGraphEdge::kInternal, "elements");
   CHECK_EQ(NULL, elements);
 }
+
+
+TEST(MapHasDescriptorsAndTransitions) {
+  v8::HandleScope scope;
+  LocalContext env;
+  CompileRun("obj = { a: 10 };\n");
+  const v8::HeapSnapshot* snapshot =
+      v8::HeapProfiler::TakeSnapshot(v8_str("snapshot"));
+  const v8::HeapGraphNode* global = GetGlobalObject(snapshot);
+  const v8::HeapGraphNode* global_object =
+      GetProperty(global, v8::HeapGraphEdge::kProperty, "obj");
+  CHECK_NE(NULL, global_object);
+  const v8::HeapGraphNode* map =
+      GetProperty(global_object, v8::HeapGraphEdge::kInternal, "map");
+  CHECK_NE(NULL, map);
+  const v8::HeapGraphNode* descriptors =
+      GetProperty(map, v8::HeapGraphEdge::kInternal, "descriptors");
+  CHECK_NE(NULL, descriptors);
+  const v8::HeapGraphNode* transitions =
+      GetProperty(map, v8::HeapGraphEdge::kInternal, "transitions");
+  CHECK_NE(NULL, transitions);
+}