bindings: Remove unnecessary idl.gni file

Those IDL files listed in the file are managed in
{core,modules}_idl_files.gni as
*_global_constructors_generated_idl_files.

Bug: None
Change-Id: I7e28508ba3388bc0a02d4537c51790cb85eec7f7
Reviewed-on: https://chromium-review.googlesource.com/999454Reviewed-by: Kenichi Ishibashi <bashi@chromium.org>
Commit-Queue: Hitoshi Yoshida <peria@chromium.org>
Cr-Commit-Position: refs/heads/master@{#548713}

third_party/WebKit/Source/bindings/idl.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.
-
-import("//third_party/WebKit/Source/bindings/bindings.gni")
-
-# Global constructors
-# FIXME: Split into core vs. modules http://crbug.com/358074
-generated_global_constructors_idl_files = [
-  "$blink_output_dir/WindowConstructors.idl",
-  "$blink_output_dir/SharedWorkerGlobalScopeConstructors.idl",
-  "$blink_output_dir/DedicatedWorkerGlobalScopeConstructors.idl",
-  "$blink_output_dir/ServiceWorkerGlobalScopeConstructors.idl",
-  "$blink_output_dir/PaintWorkletGlobalScopeConstructors.idl",
-]
-
-generated_global_constructors_header_files = [
-  "$blink_output_dir/WindowConstructors.h",
-  "$blink_output_dir/SharedWorkerGlobalScopeConstructors.h",
-  "$blink_output_dir/DedicatedWorkerGlobalScopeConstructors.h",
-  "$blink_output_dir/ServiceWorkerGlobalScopeConstructors.h",
-  "$blink_output_dir/PaintWorkletGlobalScopeConstructors.h",
-]