Backport some tests in...

Backport some tests in /components/browsing_data/core/history_notice_utils_unittest.cc to SingleThreadTaskEnvironment

These tests were previously migrated from single-threaded MessageLoop to
a multi-threaded TaskEnvironment (then named ScopedTaskEnvironment) as
part of crbug.com/891670.

//base OWNERS decided in retrospect that it was better to keep a
single-threaded option for TaskEnvironment and introduced
SingleThreadTaskEnvironment. This CL retrofits that decision for
/components/browsing_data/core/history_notice_utils_unittest.cc.

This CL is a no-op if it passes CQ.

This CL was uploaded by git cl split.

R=msarda@chromium.org

Bug: 891670
Change-Id: If2a91398d6cb6ef74600738119ed3201df26ea2e
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1786840
Auto-Submit: Gabriel Charette <gab@chromium.org>
Reviewed-by: Mihai Sardarescu <msarda@chromium.org>
Commit-Queue: Gabriel Charette <gab@chromium.org>
Cr-Commit-Position: refs/heads/master@{#695145}

components/browsing_data/core/history_notice_utils_unittest.cc

@@ -60,7 +60,7 @@ class HistoryNoticeUtilsTest : public ::testing::Test {
   std::unique_ptr<syncer::TestSyncService> sync_service_;
   std::unique_ptr<history::FakeWebHistoryService> history_service_;
 
-  base::test::TaskEnvironment task_environment_;
+  base::test::SingleThreadTaskEnvironment task_environment_;
 };
 
 TEST_F(HistoryNoticeUtilsTest, NotSyncing) {