Make sure api interceptors don't change the store target w/o storing

BUG=chromium:619166
R=verwaest@chromium.org

Review-Url: https://codereview.chromium.org/2082633002
Cr-Commit-Position: refs/heads/master@{#37152}

src/objects.cc

@@ -4307,23 +4307,38 @@ Maybe<bool> Object::SetPropertyInternal(LookupIterator* it,
         return JSProxy::SetProperty(it->GetHolder<JSProxy>(), it->GetName(),
                                     value, it->GetReceiver(), language_mode);
 
-      case LookupIterator::INTERCEPTOR:
+      case LookupIterator::INTERCEPTOR: {
+        Handle<Map> store_target_map =
+            handle(it->GetStoreTarget()->map(), it->isolate());
         if (it->HolderIsReceiverOrHiddenPrototype()) {
           Maybe<bool> result =
               JSObject::SetPropertyWithInterceptor(it, should_throw, value);
           if (result.IsNothing() || result.FromJust()) return result;
+          // Interceptor modified the store target but failed to set the
+          // property.
+          Utils::ApiCheck(*store_target_map == it->GetStoreTarget()->map(),
+                          it->IsElement() ? "v8::IndexedPropertySetterCallback"
+                                          : "v8::NamedPropertySetterCallback",
+                          "Interceptor silently changed store target.");
         } else {
           Maybe<PropertyAttributes> maybe_attributes =
               JSObject::GetPropertyAttributesWithInterceptor(it);
           if (!maybe_attributes.IsJust()) return Nothing<bool>();
-          if (maybe_attributes.FromJust() == ABSENT) break;
           if ((maybe_attributes.FromJust() & READ_ONLY) != 0) {
             return WriteToReadOnlyProperty(it, value, should_throw);
           }
+          // Interceptor modified the store target but failed to set the
+          // property.
+          Utils::ApiCheck(*store_target_map == it->GetStoreTarget()->map(),
+                          it->IsElement() ? "v8::IndexedPropertySetterCallback"
+                                          : "v8::NamedPropertySetterCallback",
+                          "Interceptor silently changed store target.");
+          if (maybe_attributes.FromJust() == ABSENT) break;
           *found = false;
           return Nothing<bool>();
         }
         break;
+      }
 
       case LookupIterator::ACCESSOR: {
         if (it->IsReadOnly()) {