Improve style delegate rendering of map themes.
Improve style delegate rendering of map themes.

Still not as neat as the native decoration, but much better than before
at least. Tested with Linux/Oxygen and Windows 7/builtin style.

CCBUG: 338039

tzapzoor/marble,probonopd/marble,tzapzoor/marble,quannt24/marble,quannt24/marble,quannt24/marble,tzapzoor/marble,tzapzoor/marble,probonopd/marble,tzapzoor/marble,tucnak/marble,tzapzoor/marble,probonopd/marble,quannt24/marble,tucnak/marble,tucnak/marble,probonopd/marble,tucnak/marble,probonopd/marble,quannt24/marble,probonopd/marble,probonopd/marble,tzapzoor/marble,tucnak/marble,tucnak/marble,quannt24/marble,tucnak/marble,quannt24/marble,tzapzoor/marble