[scheduling] Use ScopedTaskEnvironment instead of MessageLoop in bookmarks

MessageLoop will go away, eventually.

BUG=891670

Change-Id: I5d914cd64396fbc0cd3d6610981f50f8ffc0b31e
Reviewed-on: https://chromium-review.googlesource.com/c/1352263Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Carlos Caballero <carlscab@google.com>
Cr-Commit-Position: refs/heads/master@{#613135}

components/bookmarks/browser/bookmark_expanded_state_tracker_unittest.cc

@@ -8,9 +8,9 @@
 
 #include "base/files/file_path.h"
 #include "base/macros.h"
-#include "base/message_loop/message_loop.h"
 #include "base/run_loop.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/bookmarks/browser/bookmark_model.h"
 #include "components/bookmarks/common/bookmark_pref_names.h"
@@ -32,7 +32,7 @@ class BookmarkExpandedStateTrackerTest : public testing::Test {
   void SetUp() override;
   void TearDown() override;
 
-  base::MessageLoop message_loop_;
+  base::test::ScopedTaskEnvironment task_environment_;
   TestingPrefServiceSimple prefs_;
   std::unique_ptr<BookmarkModel> model_;
 

components/bookmarks/managed/BUILD.gn

@@ -35,6 +35,7 @@ source_set("unit_tests") {
   deps = [
     ":managed",
     "//base",
+    "//base/test:test_support",
     "//components/bookmarks/browser",
     "//components/bookmarks/common",
     "//components/bookmarks/test",

components/bookmarks/managed/managed_bookmarks_tracker_unittest.cc

@@ -11,9 +11,9 @@
 #include "base/files/file_path.h"
 #include "base/files/scoped_temp_dir.h"
 #include "base/memory/ptr_util.h"
-#include "base/message_loop/message_loop.h"
 #include "base/run_loop.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/bookmarks/browser/bookmark_model.h"
 #include "components/bookmarks/browser/bookmark_model_observer.h"
@@ -171,7 +171,7 @@ class ManagedBookmarksTrackerTest : public testing::Test {
   }
 
   base::ScopedTempDir scoped_temp_dir_;
-  base::MessageLoop loop_;
+  base::test::ScopedTaskEnvironment task_environment_;
   TestingPrefServiceSimple prefs_;
   std::unique_ptr<BookmarkModel> model_;
   MockBookmarkModelObserver observer_;