Use ScopedTaskEnvironment instead of MessageLoop in components unit tests.

components/google/core/browser/google_url_tracker_unittest.cc

Index: components/google/core/browser/google_url_tracker_unittest.cc
diff --git a/components/google/core/browser/google_url_tracker_unittest.cc b/components/google/core/browser/google_url_tracker_unittest.cc
index f6c325a00f8dcbef35aba8ac8a11537fe0f5124f..eed326c70f8d0b60de7f95f36fb15729473e720a 100644
--- a/components/google/core/browser/google_url_tracker_unittest.cc
+++ b/components/google/core/browser/google_url_tracker_unittest.cc
@@ -10,6 +10,7 @@
 
 #include "base/macros.h"
 #include "base/run_loop.h"
+#include "base/test/scoped_task_environment.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "components/google/core/browser/google_pref_names.h"
 #include "components/google/core/browser/google_url_tracker_client.h"
@@ -132,7 +133,7 @@ class GoogleURLTrackerTest : public testing::Test {
   void clear_listener_notified() { listener_.clear_notified(); }
 
  private:
-  base::MessageLoop message_loop_;
+  base::test::ScopedTaskEnvironment scoped_task_environment_;
   TestingPrefServiceSimple prefs_;
 
   // Creating this allows us to call