Base: Make TimeDelta constructors deal with overflow.

base/time/time.cc

Index: base/time/time.cc
diff --git a/base/time/time.cc b/base/time/time.cc
index 8cbb382bb9616dfc6ed2e7f0742630845745aa62..10ffcc606651b9a2e7ab147620d30cdb9351a443 100644
--- a/base/time/time.cc
+++ b/base/time/time.cc
@@ -144,7 +144,7 @@ Time Time::FromTimeT(time_t tt) {
     return Time();  // Preserve 0 so we can tell it doesn't exist.
   if (tt == std::numeric_limits<time_t>::max())
     return Max();
-  return Time((tt * kMicrosecondsPerSecond) + kTimeTToMicrosecondsOffset);
+  return Time(kTimeTToMicrosecondsOffset) + TimeDelta::FromSeconds(tt);
 }
 
 time_t Time::ToTimeT() const {
@@ -166,11 +166,7 @@ time_t Time::ToTimeT() const {
 Time Time::FromDoubleT(double dt) {
   if (dt == 0 || std::isnan(dt))
     return Time();  // Preserve 0 so we can tell it doesn't exist.
-  if (dt == std::numeric_limits<double>::infinity())
-    return Max();
-  return Time(static_cast<int64>((dt *
-                                  static_cast<double>(kMicrosecondsPerSecond)) +
-                                 kTimeTToMicrosecondsOffset));
+  return Time(kTimeTToMicrosecondsOffset) + TimeDelta::FromSecondsD(dt);
 }
 
 double Time::ToDoubleT() const {
@@ -197,10 +193,8 @@ Time Time::FromTimeSpec(const timespec& ts) {
 Time Time::FromJsTime(double ms_since_epoch) {
   // The epoch is a valid time, so this constructor doesn't interpret
   // 0 as the null time.
-  if (ms_since_epoch == std::numeric_limits<double>::infinity())
-    return Max();
-  return Time(static_cast<int64>(ms_since_epoch * kMicrosecondsPerMillisecond) +
-              kTimeTToMicrosecondsOffset);
+  return Time(kTimeTToMicrosecondsOffset) +
+         TimeDelta::FromMillisecondsD(ms_since_epoch);
 }
 
 double Time::ToJsTime() const {