Remove MessageLoop::current()->task_runner() in ui.

ui/views/widget/native_widget_mac_unittest.mm

Index: ui/views/widget/native_widget_mac_unittest.mm
diff --git a/ui/views/widget/native_widget_mac_unittest.mm b/ui/views/widget/native_widget_mac_unittest.mm
index f3e149a9d20823a1cb6087acacb465b8ed6110fd..0669396be3a92119714a5b16d6106cf39ebd7823 100644
--- a/ui/views/widget/native_widget_mac_unittest.mm
+++ b/ui/views/widget/native_widget_mac_unittest.mm
@@ -6,15 +6,18 @@
 
 #import <Cocoa/Cocoa.h>
 
+#include "base/location.h"
 #import "base/mac/foundation_util.h"
 #import "base/mac/scoped_nsobject.h"
 #import "base/mac/scoped_nsautorelease_pool.h"
 #import "base/mac/scoped_objc_class_swizzler.h"
 #include "base/macros.h"
 #include "base/run_loop.h"
+#include "base/single_thread_task_runner.h"
 #include "base/strings/sys_string_conversions.h"
 #include "base/strings/utf_string_conversions.h"
 #include "base/test/test_timeouts.h"
+#include "base/threading/thread_task_runner_handle.h"
 #import "testing/gtest_mac.h"
 #include "third_party/skia/include/core/SkBitmap.h"
 #include "third_party/skia/include/core/SkCanvas.h"
@@ -194,7 +197,7 @@ class WidgetChangeObserver : public TestWidgetObserver {
 
     base::RunLoop run_loop;
     run_loop_ = &run_loop;
-    base::MessageLoop::current()->task_runner()->PostDelayedTask(
+    base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
         FROM_HERE, run_loop.QuitClosure(), TestTimeouts::action_timeout());
     run_loop.Run();
     run_loop_ = nullptr;
@@ -797,7 +800,7 @@ class ScopedSwizzleWaiter {
       return;
 
     base::RunLoop run_loop;
-    base::MessageLoop::current()->task_runner()->PostDelayedTask(
+    base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
         FROM_HERE, run_loop.QuitClosure(), TestTimeouts::action_timeout());
     run_loop_ = &run_loop;
     run_loop.Run();