Add autofill preview support for <month> input fields

Source/core/html/forms/BaseMultipleFieldsDateAndTimeInputType.cpp

Index: Source/core/html/forms/BaseMultipleFieldsDateAndTimeInputType.cpp
diff --git a/Source/core/html/forms/BaseMultipleFieldsDateAndTimeInputType.cpp b/Source/core/html/forms/BaseMultipleFieldsDateAndTimeInputType.cpp
index b170ad3379c170d9f183240952adf996cec72546..51a635af9be4d246df49d4e09c1bae9f717ae46d 100644
--- a/Source/core/html/forms/BaseMultipleFieldsDateAndTimeInputType.cpp
+++ b/Source/core/html/forms/BaseMultipleFieldsDateAndTimeInputType.cpp
@@ -503,7 +503,11 @@ void BaseMultipleFieldsDateAndTimeInputType::updateView()
     DateTimeEditElement::LayoutParameters layoutParameters(element().locale(), createStepRange(AnyIsDefaultStep));
 
     DateComponents date;
-    const bool hasValue = parseToDateComponents(element().value(), &date);
+    bool hasValue = false;
+    if (!element().suggestedValue().isNull())
+        hasValue = parseToDateComponents(element().suggestedValue(), &date);
+    else
+        hasValue = parseToDateComponents(element().value(), &date);
     if (!hasValue)
         setMillisecondToDateComponents(layoutParameters.stepRange.minimum().toDouble(), &date);