Precompile mojom bindings generator jinja templates.

mojo/public/tools/bindings/generators/mojom_js_generator.py

Index: mojo/public/tools/bindings/generators/mojom_js_generator.py
diff --git a/mojo/public/tools/bindings/generators/mojom_js_generator.py b/mojo/public/tools/bindings/generators/mojom_js_generator.py
index 638f1cb0a0134d9b9fba134b98c9d309d53ea68c..e9a488388d660868d149c5c88571d55b19e4efc5 100644
--- a/mojo/public/tools/bindings/generators/mojom_js_generator.py
+++ b/mojo/public/tools/bindings/generators/mojom_js_generator.py
@@ -380,7 +380,15 @@ class Generator(generator.Generator):
       "imported_interfaces": self.GetImportedInterfaces(),
     }
 
-  @UseJinja("js_templates/module.amd.tmpl", filters=js_filters)
+  @staticmethod
+  def GetTemplatePrefix():
+    return "js_templates"
+
+  @classmethod
+  def GetFilters(cls):
+    return cls.js_filters
+
+  @UseJinja("module.amd.tmpl")
   def GenerateAMDModule(self):
     return self.GetParameters()