Derive the step base for an input element as (now) specified.

Source/core/html/forms/DateTimeLocalInputType.cpp

 /*
  * Copyright (C) 2010 Google Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are
  * met:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 68 matching lines @@
 void DateTimeLocalInputType::setValueAsDate(double value, ExceptionState& exceptionState) const
 {
     // valueAsDate doesn't work for the datetime-local type according to the standard.
     InputType::setValueAsDate(value, exceptionState);
 }
 
 StepRange DateTimeLocalInputType::createStepRange(AnyStepHandling anyStepHandling) const
 {
     DEFINE_STATIC_LOCAL(const StepRange::StepDescription, stepDescription, (dateTimeLocalDefaultStep, dateTimeLocalDefaultStepBase, dateTimeLocalStepScaleFactor, StepRange::ScaledStepValueShouldBeInteger));
 
-    const Decimal stepBase = parseToNumber(element().fastGetAttribute(minAttr), 0);
+    const Decimal stepBase = findStepBase(0);
     const Decimal minimum = parseToNumber(element().fastGetAttribute(minAttr), Decimal::fromDouble(DateComponents::minimumDateTime()));
     const Decimal maximum = parseToNumber(element().fastGetAttribute(maxAttr), Decimal::fromDouble(DateComponents::maximumDateTime()));
     const Decimal step = StepRange::parseStep(anyStepHandling, stepDescription, element().fastGetAttribute(stepAttr));
     return StepRange(stepBase, minimum, maximum, step, stepDescription);
 }
 
 bool DateTimeLocalInputType::parseToDateComponentsInternal(const String& string, DateComponents* out) const
 {
     ASSERT(out);
     unsigned end;
@@ skipping 67 matching lines @@
     layoutParameters.placeholderForYear = locale().queryString(WebLocalizedString::PlaceholderForYearField);
 }
 
 bool DateTimeLocalInputType::isValidFormat(bool hasYear, bool hasMonth, bool hasWeek, bool hasDay, bool hasAMPM, bool hasHour, bool hasMinute, bool hasSecond) const
 {
     return hasYear && hasMonth && hasDay && hasAMPM && hasHour && hasMinute;
 }
 #endif
 
 } // namespace WebCore