Remove usage time.cc of CheckedNumeric::validity()

base/time/time.h

Index: base/time/time.h
diff --git a/base/time/time.h b/base/time/time.h
index 286c0738ceb4522f791a9d9cd4ac1c67f2472ae2..1084e9517942f83c6a1a1b2831147ec648384a50 100644
--- a/base/time/time.h
+++ b/base/time/time.h
@@ -95,10 +95,6 @@ namespace time_internal {
 BASE_EXPORT int64_t SaturatedAdd(TimeDelta delta, int64_t value);
 BASE_EXPORT int64_t SaturatedSub(TimeDelta delta, int64_t value);
 
-// Clamp |value| on overflow and underflow conditions. The int64_t argument and
-// return value are in terms of a microsecond timebase.
-BASE_EXPORT int64_t FromCheckedNumeric(const CheckedNumeric<int64_t> value);
-
 }  // namespace time_internal
 
 // TimeDelta ------------------------------------------------------------------
@@ -205,13 +201,24 @@ class BASE_EXPORT TimeDelta {
   TimeDelta operator*(T a) const {
     CheckedNumeric<int64_t> rv(delta_);
     rv *= a;
-    return TimeDelta(time_internal::FromCheckedNumeric(rv));
+    if (rv.IsValid())
+      return TimeDelta(rv.ValueOrDie());
+    // Matched sign overflows. Mismatched sign underflows.
+    if ((delta_ < 0) ^ (a < 0))
+      return TimeDelta(-std::numeric_limits<int64_t>::max());
+    return TimeDelta(std::numeric_limits<int64_t>::max());
   }
   template<typename T>
   TimeDelta operator/(T a) const {
     CheckedNumeric<int64_t> rv(delta_);
     rv /= a;
-    return TimeDelta(time_internal::FromCheckedNumeric(rv));
+    if (rv.IsValid())
+      return TimeDelta(rv.ValueOrDie());
+    // Matched sign overflows. Mismatched sign underflows.
+    // Special case to catch divide by zero.
+    if ((delta_ < 0) ^ (a <= 0))
+      return TimeDelta(-std::numeric_limits<int64_t>::max());
+    return TimeDelta(std::numeric_limits<int64_t>::max());
   }
   template<typename T>
   TimeDelta& operator*=(T a) {