bindings: Make some value iterator properties aliases to Array.prototype functions

third_party/WebKit/Source/bindings/templates/interface_base.cpp.tmpl

Index: third_party/WebKit/Source/bindings/templates/interface_base.cpp.tmpl
diff --git a/third_party/WebKit/Source/bindings/templates/interface_base.cpp.tmpl b/third_party/WebKit/Source/bindings/templates/interface_base.cpp.tmpl
index e0807a7bb7f1b50008603ed66e56f95cf9e9afc5..0d3e67158dd9226945d1d4d6282221f9f08ea1c5 100644
--- a/third_party/WebKit/Source/bindings/templates/interface_base.cpp.tmpl
+++ b/third_party/WebKit/Source/bindings/templates/interface_base.cpp.tmpl
@@ -514,6 +514,14 @@ static void install{{v8_class}}Template(v8::Isolate* isolate, const DOMWrapperWo
   {% if has_array_iterator and not is_partial %}
   // Array iterator (@@iterator)
   {%+ if is_global %}instanceTemplate{% else %}prototypeTemplate{% endif %}->SetIntrinsicDataProperty(v8::Symbol::GetIterator(isolate), v8::kArrayProto_values, v8::DontEnum);
+  {% if iterable %}
+  // For value iterators, the properties below must originally be set to the corresponding ones in %ArrayPrototype%.
+  // See https://heycam.github.io/webidl/#es-iterators.
+  {%+ if is_global %}instanceTemplate{% else %}prototypeTemplate{% endif %}->SetIntrinsicDataProperty(v8AtomicString(isolate, "entries"), v8::kArrayProto_entries);

[Yuki, 2017/02/09 08:01:56]

This is just fine, but I think [Global] or [PrimaryGlobal] actually never have
iterable<T>.  I think you can write this in the following way.

  {% if is_global %}
#error "iterable<T> on [Global] is not supported."
  {% endif %}
  prototypeTemplate->SetIntrinsicDataProperty(...);

[Raphael Kubo da Costa (rakuco), 2017/02/09 10:14:28]

While I haven't encountered any uses of [Global]/[PrimaryGlobal] + iterable<> in
the wild, the spec does say it's possible.

From https://heycam.github.io/webidl/#es-iterable:

[Yuki, 2017/02/09 13:03:18]

Yes, that's true.  My point is that we don't want to introduce unused / untested
code in general.  We can add the support for [Global] later when it's really
needed.  But, meanwhile, we don't need it, we don't use it, and we don't test it
well.  Then, I think we don't want it to be landed.

+  {%+ if is_global %}instanceTemplate{% else %}prototypeTemplate{% endif %}->SetIntrinsicDataProperty(v8AtomicString(isolate, "forEach"), v8::kArrayProto_forEach);
+  {%+ if is_global %}instanceTemplate{% else %}prototypeTemplate{% endif %}->SetIntrinsicDataProperty(v8AtomicString(isolate, "keys"), v8::kArrayProto_keys);
+  {%+ if is_global %}instanceTemplate{% else %}prototypeTemplate{% endif %}->SetIntrinsicDataProperty(v8AtomicString(isolate, "values"), v8::kArrayProto_values);
+  {% endif %}
   {% endif %}
 
   {% if iterator_method %}