Add Javascript time methods to base::Time.

base/time.cc

 // Copyright (c) 2011 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 "base/time.h"
 #include "base/sys_string_conversions.h"
 #include "base/third_party/nspr/prtime.h"
 
 #include "base/logging.h"
 
@@ skipping 63 matching lines @@
 }
 
 double Time::ToDoubleT() const {
   if (us_ == 0)
     return 0;  // Preserve 0 so we can tell it doesn't exist.
   return (static_cast<double>(us_ - kTimeTToMicrosecondsOffset) /
           static_cast<double>(kMicrosecondsPerSecond));
 }
 
 // static
+Time Time::FromJsTime(double ms_since_epoch) {
+  // The epoch is a valid time, so this constructor doesn't interpret
+  // 0 as the null time.
+  return Time(static_cast<int64>(ms_since_epoch * kMicrosecondsPerMillisecond) +
+              kTimeTToMicrosecondsOffset);
+}
+
+double Time::ToJsTime() const {
+  if (us_ == 0) {

[Jeffrey Yasskin, 2012/06/08 19:20:16]

It may actually make sense to CHECK(!is_null()) here, since JS time doesn't have
an invalid value to map null to. Let me know if you want me to do that instead.

+    // Preserve 0 so the invalid result doesn't depend on the platform.
+    return 0;
+  }
+  return (static_cast<double>(us_ - kTimeTToMicrosecondsOffset) /
+          kMicrosecondsPerMillisecond);
+}
+
+// static
 Time Time::UnixEpoch() {
   Time time;
   time.us_ = kTimeTToMicrosecondsOffset;
   return time;
 }
 
 Time Time::LocalMidnight() const {
   Exploded exploded;
   LocalExplode(&exploded);
   exploded.hour = 0;
@@ skipping 31 matching lines @@
   return is_in_range(month, 1, 12) &&
          is_in_range(day_of_week, 0, 6) &&
          is_in_range(day_of_month, 1, 31) &&
          is_in_range(hour, 0, 23) &&
          is_in_range(minute, 0, 59) &&
          is_in_range(second, 0, 60) &&
          is_in_range(millisecond, 0, 999);
 }
 
 }  // namespace base