Revert of Implement timers by posting delayed tasks

public/platform/Platform.h

 /*
  * Copyright (C) 2012 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 411 matching lines @@
     // it is recommended that the fixed point be no further in the past than the epoch.
     virtual double monotonicallyIncreasingTime() { return 0; }
 
     // System trace time in seconds. For example, on Chrome OS, this timestamp should be
     // synchronized with ftrace timestamps.
     virtual double systemTraceTime() { return 0; }
 
     // WebKit clients must implement this funcion if they use cryptographic randomness.
     virtual void cryptographicallyRandomValues(unsigned char* buffer, size_t length) = 0;
 
+    // Delayed work is driven by a shared timer.
+    typedef void (*SharedTimerFunction)();
+    virtual void setSharedTimerFiredFunction(SharedTimerFunction timerFunction) { }
+    virtual void setSharedTimerFireInterval(double) { }
+    virtual void stopSharedTimer() { }
+
     // Returns an interface to the main thread. Can be null if blink was initialized on a thread without a message loop.
     BLINK_PLATFORM_EXPORT WebThread* mainThread() const;
 
     // Vibration -----------------------------------------------------------
 
     // Starts a vibration for the given duration in milliseconds. If there is currently an active
     // vibration it will be cancelled before the new one is started.
     virtual void vibrate(unsigned time) { }
 
     // Cancels the current vibration, if there is one.
@@ skipping 270 matching lines @@
 protected:
     BLINK_PLATFORM_EXPORT Platform();
     virtual ~Platform() { }
 
     WebThread* m_mainThread;
 };
 
 } // namespace blink
 
 #endif