Use the scheduling mechanism provided by the platform

Source/platform/ThreadTimers.cpp

 /*
  * Copyright (C) 2006, 2008 Apple Inc. All rights reserved.
  * Copyright (C) 2009 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
@@ skipping 13 matching lines @@
  * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
  */
 
 #include "config.h"
 #include "platform/ThreadTimers.h"
 
 #include "platform/PlatformThreadData.h"
 #include "platform/SharedTimer.h"
 #include "platform/Timer.h"
 #include "platform/TraceEvent.h"
-#include "platform/scheduler/Scheduler.h"
+#include "public/platform/Platform.h"
+#include "public/platform/WebScheduler.h"
 #include "wtf/CurrentTime.h"
 #include "wtf/MainThread.h"
 
 namespace blink {
 
 // Fire timers for this length of time, and then quit to let the run loop process user input events.
 // 100ms is about a perceptable delay in UI, so use a half of that as a threshold.
 // This is to prevent UI freeze when there are too many timers or machine performance is low.
 static const double maxDurationOfFiringTimers = 0.050;
 
@@ skipping 85 matching lines @@
         timer.setNextFireTime(interval ? fireTime + interval : 0);
 
         TRACE_EVENT2("blink", "ThreadTimers::sharedTimerFiredInternal",
             "src_file", timer.location().fileName(),
             "src_func", timer.location().functionName());
 
         // Once the timer has been fired, it may be deleted, so do nothing else with it after this point.
         timer.fired();
 
         // Catch the case where the timer asked timers to fire in a nested event loop, or we are over time limit.
-        if (!m_firingTimers || timeToQuit < monotonicallyIncreasingTime() || (isMainThread() && Scheduler::shared()->shouldYieldForHighPriorityWork()))
+        if (!m_firingTimers || timeToQuit < monotonicallyIncreasingTime())
+            break;
+
+        // Yield if there is more critical work pending on the main thread.
+        if (isMainThread() && Platform::current()->scheduler() && Platform::current()->scheduler()->shouldYieldForHighPriorityWork())

[eseidel, 2014/10/21 16:11:02]

When does this ever fire not on the main thread?  WE could just ASSERT that.

[Sami, 2014/10/21 18:49:34]

Web workers can have timers too.

             break;
     }
 
     m_firingTimers = false;
 
     updateSharedTimer();
 }
 
 void ThreadTimers::fireTimersInNestedEventLoop()
 {
     // Reset the reentrancy guard so the timers can fire again.
     m_firingTimers = false;
     updateSharedTimer();
 }
 
 } // namespace blink