[Mac] Reduce timer CPU use in MessagePumpCFRunLoopBase.

base/message_loop/message_pump_mac_unittest.cc

+// Copyright 2017 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "base/message_loop/message_pump_mac.h"
+
+#include "base/macros.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace base {
+
+class TestMessagePumpCFRunLoopBase {
+ public:
+  MessagePumpCFRunLoop message_pump;
+
+  bool CanInvalidateTimers() { return message_pump.can_invalidate_timers_; }
+};
+
+TEST(MessagePumpMacTest, TestCanInvalidateTimers) {
+  TestMessagePumpCFRunLoopBase message_pump_test;
+
+  // Catch if the use of private API ever starts failing.

[Mark Mentovai, 2017/02/21 17:41:22]

whether

[shrike, 2017/02/22 00:57:52]

Done.

+  EXPECT_TRUE(message_pump_test.CanInvalidateTimers());
+}
+}  // namespace base