Avoid unchecked casts in UA shadow DOM.

third_party/WebKit/Source/core/html/forms/MultipleFieldsTemporalInputTypeView.cpp

Index: third_party/WebKit/Source/core/html/forms/MultipleFieldsTemporalInputTypeView.cpp
diff --git a/third_party/WebKit/Source/core/html/forms/MultipleFieldsTemporalInputTypeView.cpp b/third_party/WebKit/Source/core/html/forms/MultipleFieldsTemporalInputTypeView.cpp
index daf8bad72a409ef8364d293ea19162fa7ca6ae0d..ce41b36c4c203d903a852cc4a1c04dc45e800aa4 100644
--- a/third_party/WebKit/Source/core/html/forms/MultipleFieldsTemporalInputTypeView.cpp
+++ b/third_party/WebKit/Source/core/html/forms/MultipleFieldsTemporalInputTypeView.cpp
@@ -133,25 +133,28 @@ bool DateTimeFormatValidator::validateFormat(
 
 DateTimeEditElement* MultipleFieldsTemporalInputTypeView::dateTimeEditElement()
     const {
-  return toDateTimeEditElement(element().userAgentShadowRoot()->getElementById(
-      ShadowElementNames::dateTimeEdit()));
+  return toDateTimeEditElementOrDie(
+      element().userAgentShadowRoot()->getElementById(
+          ShadowElementNames::dateTimeEdit()));
 }
 
 SpinButtonElement* MultipleFieldsTemporalInputTypeView::spinButtonElement()
     const {
-  return toSpinButtonElement(element().userAgentShadowRoot()->getElementById(
-      ShadowElementNames::spinButton()));
+  return toSpinButtonElementOrDie(
+      element().userAgentShadowRoot()->getElementById(
+          ShadowElementNames::spinButton()));
 }
 
 ClearButtonElement* MultipleFieldsTemporalInputTypeView::clearButtonElement()
     const {
-  return toClearButtonElement(element().userAgentShadowRoot()->getElementById(
-      ShadowElementNames::clearButton()));
+  return toClearButtonElementOrDie(
+      element().userAgentShadowRoot()->getElementById(
+          ShadowElementNames::clearButton()));
 }
 
 PickerIndicatorElement*
 MultipleFieldsTemporalInputTypeView::pickerIndicatorElement() const {
-  return toPickerIndicatorElement(
+  return toPickerIndicatorElementOrDie(
       element().userAgentShadowRoot()->getElementById(
           ShadowElementNames::pickerIndicator()));
 }