Use ScopedTaskEnvironment instead of MessageLoopForUI in components tests.

components/password_manager/core/browser/password_store_default_unittest.cc

Index: components/password_manager/core/browser/password_store_default_unittest.cc
diff --git a/components/password_manager/core/browser/password_store_default_unittest.cc b/components/password_manager/core/browser/password_store_default_unittest.cc
index f8239e5ceba581915b1d98ee6492bb5538786395..0e013f441e8c0398c9d8162edc7c4e4783d3c7d1 100644
--- a/components/password_manager/core/browser/password_store_default_unittest.cc
+++ b/components/password_manager/core/browser/password_store_default_unittest.cc
@@ -15,6 +15,7 @@
 #include "base/run_loop.h"
 #include "base/strings/string_util.h"
 #include "base/strings/utf_string_conversions.h"
+#include "base/test/scoped_task_environment.h"
 #include "base/threading/thread_task_runner_handle.h"
 #include "base/time/time.h"
 #include "components/password_manager/core/browser/login_database.h"
@@ -78,9 +79,10 @@ PasswordFormData CreateTestPasswordFormData() {
 
 class PasswordStoreDefaultTestDelegate {
  public:
-  PasswordStoreDefaultTestDelegate();
   explicit PasswordStoreDefaultTestDelegate(
-      std::unique_ptr<LoginDatabase> database);
+      std::unique_ptr<LoginDatabase> database)
+      : scoped_task_environment_(
+            base::test::ScopedTaskEnvironment::MainThreadType::UI) {}

[gab, 2017/04/28 01:43:00]

Deleting the default constructor and forcing this one here are both unepxected
(already defined below)

[fdoray, 2017/05/01 17:16:51]

Done.

   ~PasswordStoreDefaultTestDelegate();
 
   PasswordStoreDefault* store() { return store_.get(); }
@@ -97,7 +99,7 @@ class PasswordStoreDefaultTestDelegate {
 
   base::FilePath test_login_db_file_path() const;
 
-  base::MessageLoopForUI message_loop_;
+  base::test::ScopedTaskEnvironment scoped_task_environment_;
   base::ScopedTempDir temp_dir_;
   scoped_refptr<PasswordStoreDefault> store_;