Remove unnecessary wrapper on DomHighResTimestamp, and clamp resolution to 1 millisecond

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

 // Copyright 2016 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "core/timing/PerformanceLongTaskTiming.h"
 
 #include "core/frame/DOMWindow.h"
 
 namespace blink {
 
+namespace {
+
+double clampToMillisecond(double timeInMillis) {
+  // Long task times are clamped to 1 millisecond for security.
+  return floor(timeInMillis);
+}
+
+}  // namespace
+
 PerformanceLongTaskTiming::PerformanceLongTaskTiming(double startTime,
                                                      double endTime,
                                                      String name,
                                                      String culpritFrameSrc,
                                                      String culpritFrameId,
                                                      String culpritFrameName)
-    : PerformanceEntry(name, "longtask", startTime, endTime),
+    : PerformanceEntry(name,
+                       "longtask",
+                       clampToMillisecond(startTime),
+                       clampToMillisecond(endTime)),
       m_culpritFrameSrc(culpritFrameSrc),
       m_culpritFrameId(culpritFrameId),
       m_culpritFrameName(culpritFrameName) {}
 
 PerformanceLongTaskTiming::~PerformanceLongTaskTiming() {}
 
 String PerformanceLongTaskTiming::culpritFrameSrc() const {
   return m_culpritFrameSrc;
 }
 
 String PerformanceLongTaskTiming::culpritFrameId() const {
   return m_culpritFrameId;
 }
 
 String PerformanceLongTaskTiming::culpritFrameName() const {
   return m_culpritFrameName;
 }
 
 DEFINE_TRACE(PerformanceLongTaskTiming) {
   PerformanceEntry::trace(visitor);
 }
 
 }  // namespace blink