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 70 matching lines @@
       timeout_id_(timeout_id),
       nesting_level_(context->Timers()->TimerNestingLevel() + 1),
       action_(action) {
   ASSERT(timeout_id > 0);
   if (ShouldForwardUserGesture(interval, nesting_level_)) {
     // Thread safe because shouldForwardUserGesture will only return true if
     // execution is on the the main thread.
     user_gesture_token_ = UserGestureIndicator::CurrentToken();
   }
 
+  // TODO(delphick): Remove the single shot guard here so that this affects
+  // setInterval as well.
   double interval_milliseconds =
-      std::max(kOneMillisecond, interval * kOneMillisecond);
+      std::max(single_shot ? 0.0 : kOneMillisecond, interval * kOneMillisecond);
   if (interval_milliseconds < kMinimumInterval &&
       nesting_level_ >= kMaxTimerNestingLevel)
     interval_milliseconds = kMinimumInterval;
   if (single_shot)
     StartOneShot(interval_milliseconds, BLINK_FROM_HERE);
   else
     StartRepeating(interval_milliseconds, BLINK_FROM_HERE);
 
   SuspendIfNeeded();
   TRACE_EVENT_INSTANT1("devtools.timeline", "TimerInstall",
@@ skipping 83 matching lines @@
 RefPtr<WebTaskRunner> DOMTimer::TimerTaskRunner() const {
   return GetExecutionContext()->Timers()->TimerTaskRunner();
 }
 
 DEFINE_TRACE(DOMTimer) {
   visitor->Trace(action_);
   SuspendableTimer::Trace(visitor);
 }
 
 }  // namespace blink