Use ScopedTaskEnvironment instead of MessageLoopForUI in components tests.

components/history/core/browser/history_service_unittest.cc

Index: components/history/core/browser/history_service_unittest.cc
diff --git a/components/history/core/browser/history_service_unittest.cc b/components/history/core/browser/history_service_unittest.cc
index b26d83adbbb7ffa3520e601c235939bfcbf65aa9..29ac63f24d02d6b5334858484de3bee2ec1b94ae 100644
--- a/components/history/core/browser/history_service_unittest.cc
+++ b/components/history/core/browser/history_service_unittest.cc
@@ -29,6 +29,7 @@
 #include "base/run_loop.h"
 #include "base/single_thread_task_runner.h"
 #include "base/strings/utf_string_conversions.h"
+#include "base/test/scoped_task_environment.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "components/history/core/browser/history_database_params.h"
 #include "components/history/core/browser/history_db_task.h"
@@ -51,7 +52,10 @@ namespace history {
 
 class HistoryServiceTest : public testing::Test {
  public:
-  HistoryServiceTest() : query_url_success_(false) {}
+  HistoryServiceTest()
+      : scoped_task_environment_(
+            base::test::ScopedTaskEnvironment::MainThreadType::UI),
+        query_url_success_(false) {}
 
   ~HistoryServiceTest() override {}
 
@@ -154,7 +158,7 @@ class HistoryServiceTest : public testing::Test {
 
   base::ScopedTempDir temp_dir_;
 
-  base::MessageLoopForUI message_loop_;
+  base::test::ScopedTaskEnvironment scoped_task_environment_;
 
   MostVisitedURLList most_visited_urls_;