Fix name shown by devtools for subclasses.

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 9bdd3b81e66e6778349729291fcf5a0366db4687..d4e4cfb19c6a54de4a4a1d40d35ad0c2ad02a3d5 100644
--- a/test/cctest/test-heap-profiler.cc
+++ b/test/cctest/test-heap-profiler.cc
@@ -1818,11 +1818,11 @@ TEST(GetConstructorName) {
       "var Constructor2 = function() {};\n"
       "var obj2 = new Constructor2();\n"
       "var obj3 = {};\n"
-      "obj3.constructor = function Constructor3() {};\n"
+      "obj3.__proto__ = { constructor: function Constructor3() {} };\n"
       "var obj4 = {};\n"
       "// Slow properties\n"
       "for (var i=0; i<2000; ++i) obj4[\"p\" + i] = i;\n"
-      "obj4.constructor = function Constructor4() {};\n"
+      "obj4.__proto__ = { constructor: function Constructor4() {} };\n"
       "var obj5 = {};\n"
       "var obj6 = {};\n"
       "obj6.constructor = 6;");
@@ -1838,16 +1838,12 @@ TEST(GetConstructorName) {
       "Constructor2", i::V8HeapExplorer::GetConstructorName(*js_obj2)));
   v8::Local<v8::Object> obj3 = js_global->Get(v8_str("obj3")).As<v8::Object>();
   i::Handle<i::JSObject> js_obj3 = v8::Utils::OpenHandle(*obj3);
-  // TODO(verwaest): Restore to Constructor3 once supported by the
-  // heap-snapshot-generator.
-  CHECK_EQ(
-      0, StringCmp("Object", i::V8HeapExplorer::GetConstructorName(*js_obj3)));
+  CHECK_EQ(0, StringCmp("Constructor3",
+                        i::V8HeapExplorer::GetConstructorName(*js_obj3)));
   v8::Local<v8::Object> obj4 = js_global->Get(v8_str("obj4")).As<v8::Object>();
   i::Handle<i::JSObject> js_obj4 = v8::Utils::OpenHandle(*obj4);
-  // TODO(verwaest): Restore to Constructor4 once supported by the
-  // heap-snapshot-generator.
-  CHECK_EQ(
-      0, StringCmp("Object", i::V8HeapExplorer::GetConstructorName(*js_obj4)));
+  CHECK_EQ(0, StringCmp("Constructor4",
+                        i::V8HeapExplorer::GetConstructorName(*js_obj4)));
   v8::Local<v8::Object> obj5 = js_global->Get(v8_str("obj5")).As<v8::Object>();
   i::Handle<i::JSObject> js_obj5 = v8::Utils::OpenHandle(*obj5);
   CHECK_EQ(0, StringCmp(