Track computed literal properties.

src/runtime.cc

Index: src/runtime.cc
diff --git a/src/runtime.cc b/src/runtime.cc
index c47e35d3aeabb4be51a4a0d42c1824f875fad45c..75ace335b63a88222c2fa2ca5bfe6ddf64044705 100644
--- a/src/runtime.cc
+++ b/src/runtime.cc
@@ -255,12 +255,15 @@ static Handle<Object> CreateObjectLiteralBoilerplate(
   for (int index = 0; index < length; index +=2) {
     Handle<Object> key(constant_properties->get(index+0), isolate);
     Handle<Object> value(constant_properties->get(index+1), isolate);
+    Object::ValueType value_type = Object::REAL_VALUE;
     if (value->IsFixedArray()) {
       // The value contains the constant_properties of a
       // simple object or array literal.
       Handle<FixedArray> array = Handle<FixedArray>::cast(value);
       value = CreateLiteralBoilerplate(isolate, literals, array);
       if (value.is_null()) return value;
+    } else if (FLAG_track_computed_fields && value->IsUndefined()) {
+      value_type = Object::PLACEHOLDER_VALUE;
     }
     Handle<Object> result;
     uint32_t element_index = 0;
@@ -273,7 +276,7 @@ static Handle<Object> CreateObjectLiteralBoilerplate(
         Handle<String> name(String::cast(*key));
         ASSERT(!name->AsArrayIndex(&element_index));
         result = JSObject::SetLocalPropertyIgnoreAttributes(
-            boilerplate, name, value, NONE);
+            boilerplate, name, value, NONE, value_type);
       }
     } else if (key->ToArrayIndex(&element_index)) {
       // Array index (uint32).
@@ -289,7 +292,7 @@ static Handle<Object> CreateObjectLiteralBoilerplate(
       Handle<String> name =
           isolate->factory()->NewStringFromAscii(CStrVector(str));
       result = JSObject::SetLocalPropertyIgnoreAttributes(
-          boilerplate, name, value, NONE);
+          boilerplate, name, value, NONE, value_type);
     }
     // If setting the property on the boilerplate throws an
     // exception, the exception is converted to an empty handle in