Use implicit_cast<> instead of static_cast<> whenever possible

util/net/http_transport_mac.mm

Index: util/net/http_transport_mac.mm
diff --git a/util/net/http_transport_mac.mm b/util/net/http_transport_mac.mm
index a56499a60b6a3ca8e1fd1dbe19e057e522814bb8..2170b1ff83bf6824ad7d1f460521564e633df0e6 100644
--- a/util/net/http_transport_mac.mm
+++ b/util/net/http_transport_mac.mm
@@ -174,7 +174,7 @@ bool HTTPTransportMac::ExecuteSynchronously() {
     NSInteger http_status = [http_response statusCode];
     if (http_status != 200) {
       LOG(ERROR) << base::StringPrintf("HTTP status %ld",
-                                       static_cast<long>(http_status));
+                                       implicit_cast<long>(http_status));
       return false;
     }