binding: Updates a comment of the class string on the platform objects.

third_party/WebKit/Source/bindings/core/v8/V8DOMConfiguration.cpp

Index: third_party/WebKit/Source/bindings/core/v8/V8DOMConfiguration.cpp
diff --git a/third_party/WebKit/Source/bindings/core/v8/V8DOMConfiguration.cpp b/third_party/WebKit/Source/bindings/core/v8/V8DOMConfiguration.cpp
index 5fc33c7fbad0940f02745ce596eb3c93264c50bb..79aceb59f7ce83e074b5981136fe5dff7ca6c4f9 100644
--- a/third_party/WebKit/Source/bindings/core/v8/V8DOMConfiguration.cpp
+++ b/third_party/WebKit/Source/bindings/core/v8/V8DOMConfiguration.cpp
@@ -616,12 +616,19 @@ void V8DOMConfiguration::initializeDOMInterfaceTemplate(
   v8::Local<v8::ObjectTemplate> prototypeTemplate =
       interfaceTemplate->PrototypeTemplate();
   instanceTemplate->SetInternalFieldCount(v8InternalFieldCount);
-  // TODO(yukishiino): We should set the class string to the platform object
-  // (|instanceTemplate|), too.  The reason that we don't set it is that
-  // it prevents minor GC to collect unreachable DOM objects (a layout test
-  // fast/dom/minor-dom-gc.html fails if we set the class string).
-  // See also http://heycam.github.io/webidl/#es-platform-objects
+
+  // We intentionally don't set the class string to the platform object
+  // (|instanceTemplate|), and set the class string "InterfaceName", without
+  // "Prototype", to the prototype object (|prototypeTemplate|), because we

[Matt Giuca, 2017/02/05 23:18:08]

It seems a bit strange out of context to be saying "without "Prototype""... why
would there be an expectation of it having "Prototype" at the end?

Perhaps add "(as required by the current WebIDL draft, as of February 2017)" or
something, to say basically this comment marks an explicit deviation from the
draft standard.

[Yuki, 2017/02/14 12:58:46]

Done.

+  // think it's more consistent with ECMAScript 2016.
+  // See also https://crbug.com/643712
+  //
+  // Note that V8 minor GC does not collect an object which has an own property.
+  // So, if we set the class string to the platform object as an own property,
+  // it prevents V8 minor GC to collect the object (V8 minor GC only collects
+  // an empty object).  If set, a layout test fast/dom/minor-dom-gc.html fails.
   setClassString(isolate, prototypeTemplate, interfaceName);
+
   if (!parentInterfaceTemplate.IsEmpty()) {
     interfaceTemplate->Inherit(parentInterfaceTemplate);
     // Marks the prototype object as one of native-backed objects.