Implement MessagePumpDefault::SetTimerSlack on Mac.

Bug: 753544
Change-Id: If64adc488f637b9970f11ef5c0b32aab906a84e0
Reviewed-on: https://chromium-review.googlesource.com/615445
Reviewed-by: Mark Mentovai <[email protected]>
Commit-Queue: Robert Sesek <[email protected]>
Cr-Commit-Position: refs/heads/master@{#503899}
diff --git a/base/message_loop/message_pump_default.h b/base/message_loop/message_pump_default.h
index 4cd7cd1..dd11adc 100644
--- a/base/message_loop/message_pump_default.h
+++ b/base/message_loop/message_pump_default.h
@@ -10,6 +10,7 @@
 #include "base/message_loop/message_pump.h"
 #include "base/synchronization/waitable_event.h"
 #include "base/time/time.h"
+#include "build/build_config.h"
 
 namespace base {
 
@@ -23,6 +24,9 @@
   void Quit() override;
   void ScheduleWork() override;
   void ScheduleDelayedWork(const TimeTicks& delayed_work_time) override;
+#if defined(OS_MACOSX)
+  void SetTimerSlack(TimerSlack timer_slack) override;
+#endif
 
  private:
   // This flag is set to false when Run should return.