Use implicit_cast<> instead of static_cast<> whenever possible

util/mach/mach_message_server.cc

Index: util/mach/mach_message_server.cc
diff --git a/util/mach/mach_message_server.cc b/util/mach/mach_message_server.cc
index 0c1745d6598d75b43e24caa99b1f39ed59f06ce7..5ac9f42e7091e0494d1abb693fcc6343c5be94cf 100644
--- a/util/mach/mach_message_server.cc
+++ b/util/mach/mach_message_server.cc
@@ -95,7 +95,7 @@ mach_msg_return_t MachMessageServer::Run(Interface* interface,
   } else if (timeout_ms != MACH_MSG_TIMEOUT_NONE) {
     options |= timeout_options;
     deadline = ClockMonotonicNanoseconds() +
-               static_cast<uint64_t>(timeout_ms) * kNanosecondsPerMillisecond;
+               implicit_cast<uint64_t>(timeout_ms) * kNanosecondsPerMillisecond;
   } else {
     options &= ~timeout_options;
     deadline = 0;