Make constructors in Worklets be properly exposed on the global.

third_party/WebKit/Source/bindings/modules/modules.gni

 # Copyright 2014 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 # FIXME: factor out bindings_core http://crbug.com/358074
 import("//third_party/WebKit/Source/bindings/bindings.gni")
 import("//third_party/WebKit/Source/modules/modules.gni")
 
 bindings_modules_output_dir = "$bindings_output_dir/modules"
 
 modules_core_global_constructors_original_interfaces = [
   "CompositorWorkerGlobalScope",
+  "PaintWorkletGlobalScope",
   "ServiceWorkerGlobalScope",
 ]
 
 modules_global_constructors_original_interfaces = [
   "Window",
   "CompositorWorkerGlobalScope",
   "DedicatedWorkerGlobalScope",
+  "PaintWorkletGlobalScope",
   "ServiceWorkerGlobalScope",
   "SharedWorkerGlobalScope",
 ]
 
 modules_core_global_constructors_generated_idl_files = []
 foreach(interface, modules_core_global_constructors_original_interfaces) {
   modules_core_global_constructors_generated_idl_files +=
       [ "$blink_modules_output_dir/${interface}CoreConstructors.idl" ]
 }
 
 modules_global_constructors_generated_idl_files = []
 foreach(interface, modules_global_constructors_original_interfaces) {
   modules_global_constructors_generated_idl_files +=
       [ "$blink_modules_output_dir/${interface}ModulesConstructors.idl" ]
 }