Use WTF::TimeTicks to represent timestamp in Platform/Core event types

third_party/WebKit/Source/wtf/Time.h

 // 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.
 
 #ifndef WTF_Time_h
 #define WTF_Time_h
 
 #include "base/time/time.h"
 #include "wtf/CurrentTime.h"
 
@@ skipping 25 matching lines @@
       double seconds = (WTF::getTimeFunctionForTesting())();
       return TimeWrapper() + TimeDelta::FromSecondsD(seconds);
     }
     return TimeWrapper(WrappedTimeType::Now());
   }
 
   int64_t ToInternalValueForTesting() const {
     return m_value.ToInternalValue();
   }
 
+  // Only use this conversion when interfacing with legacy code that represents
+  // time in double. Converting to double can lead to losing information for
+  // large time values.
+  double InSeconds() const {
+    return (m_value - WrappedTimeType()).InSecondsF();
+  }
+
+  static TimeWrapper FromSeconds(double seconds) {
+    return WrappedTimeType() + TimeDelta::FromSecondsD(seconds);
+  }
+
   TimeWrapper& operator=(TimeWrapper other) {
     m_value = other.m_value;
     return *this;
   }
 
   TimeDelta operator-(TimeWrapper other) const {
     return m_value - other.m_value;
   }
 
   TimeWrapper operator+(TimeDelta delta) const {
@@ skipping 29 matching lines @@
 using Time = internal::TimeWrapper<base::Time>;
 using TimeTicks = internal::TimeWrapper<base::TimeTicks>;
 
 }  // namespace WTF
 
 using WTF::Time;
 using WTF::TimeDelta;
 using WTF::TimeTicks;
 
 #endif  // Time_h