Method to convet base::Time to Java timestamp.

base/time/time.h

Index: base/time/time.h
diff --git a/base/time/time.h b/base/time/time.h
index af95700ac1eba3727db023c5ef6f8f000eea3add..c940847fb3bcb339b858aeeea4abcc9f3ac7bba3 100644
--- a/base/time/time.h
+++ b/base/time/time.h
@@ -300,6 +300,10 @@ class BASE_EXPORT Time {
   static Time FromJsTime(double ms_since_epoch);
   double ToJsTime() const;
 
+  // Converts to Java convention for times, a number of
+  // milliseconds since the epoch.
+  int64 ToJavaTime() const;
+
 #if defined(OS_POSIX)
   static Time FromTimeVal(struct timeval t);
   struct timeval ToTimeVal() const;