Add support for named arguments to our bindings generation.

This doesn't yet support having both named and optional
arguments, but once I have an example of that it should
be trivial to add.

I also cleaned up the generation a little so the generated
dart file looks nicer. :)

R=abarth@chromium.org
BUG=

Review URL: https://codereview.chromium.org/923093003

engine/bindings/IDLExtendedAttributes.txt

@@ -55,6 +55,7 @@ ImplementedAs=*
 InitializedByEventConstructor
 Iterable
 LegacyTreatAsPartialInterface
+Named
 NamedConstructor=*
 NoImplHeader
 NoInterfaceObject
@@ -70,9 +71,9 @@ ReflectInvalid=*
 ReflectMissing=*
 ReflectOnly=*
 Replaceable
+SetterCallWith=ExecutionContext|ScriptArguments|ActiveWindow|FirstWindow
 SetWrapperReferenceFrom=*
 SetWrapperReferenceTo=*
-SetterCallWith=ExecutionContext|ScriptArguments|ActiveWindow|FirstWindow
 SpecialWrapFor=*
 TreatNullAs=NullString|EmptyString
 TreatReturnedNullStringAs=Null|Undefined

engine/bindings/scripts/dart_methods.py

@@ -125,6 +125,7 @@ def argument_context(interface, method, argument, index):
         'local_cpp_type': local_cpp_type,
         # FIXME: check that the default value's type is compatible with the argument's
         'default_value': default_value,
+        'is_named': 'Named' in extended_attributes,
         'dart_default_value': dart_default_value,
         'enum_validation_expression': idl_type.enum_validation_expression,
         'preprocessed_type': preprocessed_type,

engine/bindings/scripts/templates/interface_dart.template

@@ -5,23 +5,24 @@
 // WARNING: Do not edit - generated code.
 part of sky.core;
 
-abstract class {{interface_name}} extends {{ parent_interface if parent_interface else 'NativeFieldWrapperClass2' }} {
-
 {% macro args_macro(args) -%}
     {%- for arg in args -%}
         {%- if arg.is_optional and (loop.first or not args[arg.index-1].is_optional) -%}
-        [
+        {{ '{' if arg.is_named else '[' }}
         {%- endif -%}
         {{ arg.dart_type }} {{ arg.name }}
         {%- if arg.is_optional %} = {{ arg.dart_default_value }}
-        {%- if loop.last -%}]{%- endif -%}
+        {#- TODO(eseidel): This does not support having both optional and named arguments! -#}
+        {%- if loop.last -%}{{ '}' if arg.is_named else ']' }}{%- endif -%}
         {%- endif -%}
         {%- if not loop.last %}, {% endif %}
     {%- endfor -%}
-{%- endmacro %}
+{%- endmacro -%}
 
+abstract class {{interface_name}} extends {{ parent_interface if parent_interface else 'NativeFieldWrapperClass2' }} {
+    // Constructors
 {# TODO(eseidel): We only ever have one constructor. #}
-{% for constructor in constructors %}
+{%- for constructor in constructors -%}
     static {{interface_name}} _constructor({{ args_macro(constructor.arguments) }}) native "{{interface_name}}_constructorCallback";
     factory {{interface_name}}({{ args_macro(constructor.arguments) }}) => _constructor(
     {%- for arg in constructor.arguments -%}
@@ -30,6 +31,7 @@ abstract class {{interface_name}} extends {{ parent_interface if parent_interfac
     );
 {% endfor %}
 
+    // Attributes
 {% for attribute in attributes %}
     {{ attribute.dart_type }} get {{ attribute.name }} native "{{interface_name}}_{{ attribute.name }}_Getter";
 {% if not attribute.is_read_only %}
@@ -37,7 +39,8 @@ abstract class {{interface_name}} extends {{ parent_interface if parent_interfac
 {% endif %}
 {% endfor %}
 
+    // Methods
 {% for method in methods %}
-    {{method.dart_type}} {{method.name}}({{ args_macro(method.arguments)}} ) native "{{interface_name}}_{{ method.name }}_Callback";
+    {{method.dart_type}} {{method.name}}({{ args_macro(method.arguments)}}) native "{{interface_name}}_{{ method.name }}_Callback";
 {% endfor %}
 }

engine/core/dom/Node.idl

@@ -3,8 +3,7 @@
 // found in the LICENSE file.
 
 interface Node : EventTarget {
-  // TODO(abarth): This should actually be a named argument.
-  Node cloneNode(optional boolean deep);
+  Node cloneNode([Named] optional boolean deep = true);
 
   readonly attribute ParentNode owner;
   readonly attribute ParentNode parentNode;