aOutputString.Append(NS_LITERAL_STRING("px"));
aOutputString.AppendLiteral("px");
void ProcessLengthValue(const nsAString * aInputString, nsAString & aOutputString,                        const char * aDefaultValueString,                        const char * aPrependString, const char* aAppendString){  aOutputString.Truncate();  if (aInputString) {    aOutputString.Append(*aInputString);    if (-1 == aOutputString.FindChar(PRUnichar('%'))) {      aOutputString.Append(NS_LITERAL_STRING("px"));    }  }}