No longer clamp setTimeout(..., 0) to 1ms.

third_party/WebKit/Source/core/frame/DOMTimer.cpp

 /*
  * Copyright (C) 2008 Apple 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
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 75 matching lines @@
       m_nestingLevel(context->timers()->timerNestingLevel() + 1),
       m_action(action) {
   ASSERT(timeoutID > 0);
   if (shouldForwardUserGesture(interval, m_nestingLevel)) {
     // Thread safe because shouldForwardUserGesture will only return true if
     // execution is on the the main thread.
     m_userGestureToken = UserGestureIndicator::currentToken();
   }
 
   double intervalMilliseconds =
-      std::max(oneMillisecond, interval * oneMillisecond);
+      std::max(singleShot ? 0.0 : oneMillisecond, interval * oneMillisecond);

[Sami, 2017/03/08 14:15:55]

Did we try to make the minimum always be 0 for all types of timers? That's what
the spec calls for I think. Maybe add a TODO for that here?

   if (intervalMilliseconds < minimumInterval &&
       m_nestingLevel >= maxTimerNestingLevel)
     intervalMilliseconds = minimumInterval;
   if (singleShot)
     startOneShot(intervalMilliseconds, BLINK_FROM_HERE);
   else
     startRepeating(intervalMilliseconds, BLINK_FROM_HERE);
 
   suspendIfNeeded();
   probe::asyncTaskScheduledBreakable(
@@ skipping 82 matching lines @@
 RefPtr<WebTaskRunner> DOMTimer::timerTaskRunner() const {
   return getExecutionContext()->timers()->timerTaskRunner();
 }
 
 DEFINE_TRACE(DOMTimer) {
   visitor->trace(m_action);
   SuspendableTimer::trace(visitor);
 }
 
 }  // namespace blink