Oilpan: move BaseChooserOnlyDateAndTimeInputType to the heap.

third_party/WebKit/Source/core/html/forms/MonthInputType.h

Index: third_party/WebKit/Source/core/html/forms/MonthInputType.h
diff --git a/third_party/WebKit/Source/core/html/forms/MonthInputType.h b/third_party/WebKit/Source/core/html/forms/MonthInputType.h
index 3b1af1c71cb57bbec9bfe9a6febbd63f0e1afb81..fec9113b38ad05a4ca24bfbf3eb4475639553626 100644
--- a/third_party/WebKit/Source/core/html/forms/MonthInputType.h
+++ b/third_party/WebKit/Source/core/html/forms/MonthInputType.h
@@ -43,11 +43,14 @@ using BaseMonthInputType = BaseChooserOnlyDateAndTimeInputType;
 #endif
 
 class MonthInputType final : public BaseMonthInputType {
+    WILL_BE_USING_GARBAGE_COLLECTED_MIXIN(MonthInputType);

[haraken, 2015/11/21 17:10:22]

I'm a bit confused. Why does this need to use USING_GC_MIXIN? Both
BaseMultipleFieldsDateAndTimeInputType and BaseChooserOnlyDateAndTimeInputType
inherits from GarbageCollected and no mixin class is inherited by
MonthInputType...

(I think I'm missing something.)

[sof, 2015/11/21 17:26:20]

It only needs it !ENABLE(INPUT_MULTIPLE_FIELDS_UI) for DateTimeChooserClient.

[sof, 2015/11/21 17:41:52]

I'll make that more precise, at the cost of some #if-ery.

 public:
     static PassRefPtrWillBeRawPtr<InputType> create(HTMLInputElement&);
+    DEFINE_INLINE_VIRTUAL_TRACE() { BaseMonthInputType::trace(visitor); }
 
 private:
-    MonthInputType(HTMLInputElement& element) : BaseMonthInputType(element) { }
+    explicit MonthInputType(HTMLInputElement& element) : BaseMonthInputType(element) { }
+
     void countUsage() override;
     const AtomicString& formControlType() const override;
     double valueAsDate() const override;