Mojo C++ bindings: assume that all imported mojoms have the same variant as current mojom

mojo/public/tools/bindings/generators/cpp_templates/module.h.tmpl

Index: mojo/public/tools/bindings/generators/cpp_templates/module.h.tmpl
diff --git a/mojo/public/tools/bindings/generators/cpp_templates/module.h.tmpl b/mojo/public/tools/bindings/generators/cpp_templates/module.h.tmpl
index 901fa69e1f4e4867a53fec82a5960a37af320e07..d506e6c56e47bdb505843388f45c3e0020f8a481 100644
--- a/mojo/public/tools/bindings/generators/cpp_templates/module.h.tmpl
+++ b/mojo/public/tools/bindings/generators/cpp_templates/module.h.tmpl
@@ -35,7 +35,11 @@
 #include "mojo/public/cpp/bindings/struct_traits.h"
 #include "{{variant_path}}-internal.h"
 {%- for import in imports %}
+{%-   if variant %}
+#include "{{"%s-%s.h"|format(import.module.path, variant)}}"
+{%-   else %}
 #include "{{import.module.path}}.h"
+{%-   endif %}
 {%- endfor %}
 {%- if not for_blink %}
 #include "mojo/public/cpp/bindings/array.h"