[privacy_budget] Remove unused file.

R=pauljensen@chromium.org

Bug: 973801
Change-Id: I245cf214f86b56d1e304ae252e23039417db4631
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2315168
Commit-Queue: Paul Jensen <pauljensen@chromium.org>
Auto-Submit: Asanka Herath <asanka@chromium.org>
Reviewed-by: Paul Jensen <pauljensen@chromium.org>
Cr-Commit-Position: refs/heads/master@{#791336}

chrome/browser/privacy_budget/internal_unordered_container_ops_unittest.cc

-// Copyright 2020 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.
-
-#include "chrome/common/privacy_budget/container_ops.h"