Revert of Added DCHECK for monotonicTimeToDOMHighResTimeStamp in PerformanceBase

third_party/WebKit/Source/core/timing/PerformanceBase.cpp

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  * Copyright (C) 2012 Intel 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.
@@ skipping 562 matching lines @@
 }
 
 DOMHighResTimeStamp PerformanceBase::monotonicTimeToDOMHighResTimeStamp(
     double timeOrigin,
     double monotonicTime) {
   // Avoid exposing raw platform timestamps.
   if (!monotonicTime || !timeOrigin)
     return 0.0;
 
   double timeInSeconds = monotonicTime - timeOrigin;
-  DCHECK_GE(timeInSeconds, 0);
+  if (timeInSeconds < 0)
+    return 0.0;
   return convertSecondsToDOMHighResTimeStamp(
       clampTimeResolution(timeInSeconds));
 }
 
 DOMHighResTimeStamp PerformanceBase::monotonicTimeToDOMHighResTimeStamp(
     double monotonicTime) const {
   return monotonicTimeToDOMHighResTimeStamp(m_timeOrigin, monotonicTime);
 }
 
 DOMHighResTimeStamp PerformanceBase::now() const {
   return monotonicTimeToDOMHighResTimeStamp(monotonicallyIncreasingTime());
 }
 
 DEFINE_TRACE(PerformanceBase) {
   visitor->trace(m_frameTimingBuffer);
   visitor->trace(m_resourceTimingBuffer);
   visitor->trace(m_navigationTiming);
   visitor->trace(m_userTiming);
   visitor->trace(m_observers);
   visitor->trace(m_activeObservers);
   visitor->trace(m_suspendedObservers);
   EventTargetWithInlineData::trace(visitor);
 }
 
 }  // namespace blink