Generate java bindings for structs.

mojo/public/tools/bindings/generators/java_templates/struct_definition.tmpl

+{% from "constant_definition.tmpl" import constant_def %}
+{% from "enum_definition.tmpl" import enum_def %}
+
+{% macro struct_def(struct, inner_class=False) %}
+{{'static' if inner_class else 'public'}} final class {{struct|name}} extends org.chromium.mojo.bindings.Struct {
+{%  for constant in struct.constants %}
+
+    {{constant_def(constant)|indent(4)}}
+{%  endfor %}
+{%  for enum in struct.enums %}
+
+    {{enum_def(enum, false)|indent(4)}}
+{% endfor %}
+{% if struct.fields %}
+
+{%   for field in struct.fields %}
+    public {{field.kind|java_type}} {{field|name}};
+{%   endfor %}
+{% endif %}
+
+    public {{struct|name}}() {
+{% for field in struct.fields %}
+{%   if field.default %}
+        {{field|name}} = {{field|default_value}};
+{%   elif field.kind|is_handle %}
+        {{field|name}} = org.chromium.mojo.system.InvalidHandle.INSTANCE;
+{%   endif %}
+{% endfor %}
+    }
+
+}
+{% endmacro %}