Chime: Delete unused module declaration.

Chime DFM has been moved to downstream. The upstream DFM declaration
file and BUILD.gn file can be deleted now.

Bug: NONE
Change-Id: I8b624ace8e558aee4d1416f9b6b0e8a36d338ae5
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2523524
Commit-Queue: Xing Liu <xingliu@chromium.org>
Reviewed-by: Mohamed Heikal <mheikal@chromium.org>
Reviewed-by: Peter Wen <wnwen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#825920}

chrome/android/modules/chime/chime_module.gni

-# Copyright 2019 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.
-
-declare_args() {
-  # temporarily disable chime sdk while migration downstream is in progress.
-  # crbug.com/1142775
-  use_chime_android_sdk = false
-}

chrome/android/modules/chime/public/BUILD.gn

-# Copyright 2019 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("//build/config/android/rules.gni")
-
-# Empty target to prevent downstream breaking.
-java_group("java") {
-}