--- a/dom/html/HTMLInputElement.cpp
+++ b/dom/html/HTMLInputElement.cpp
@@ -1366,20 +1366,16 @@ HTMLInputElement::BeforeSetAttr(int32_t 
 
         LoadImage(aValue->String(), true, aNotify, eImageLoadType_Normal);
       } else {
         // Null value means the attr got unset; drop the image
         CancelImageRequests(aNotify);
       }
     } else if (aNotify && aName == nsGkAtoms::disabled) {
       mDisabledChanged = true;
-    } else if (aName == nsGkAtoms::dir &&
-               AttrValueIs(kNameSpaceID_None, nsGkAtoms::dir,
-                           nsGkAtoms::_auto, eIgnoreCase)) {
-      SetDirectionIfAuto(false, aNotify);
     } else if (mType == NS_FORM_INPUT_RADIO && aName == nsGkAtoms::required) {
       nsCOMPtr<nsIRadioGroupContainer> container = GetRadioGroupContainer();
 
       if (container &&
           ((aValue && !HasAttr(aNameSpaceID, aName)) ||
            (!aValue && HasAttr(aNameSpaceID, aName)))) {
         nsAutoString name;
         GetAttr(kNameSpaceID_None, nsGkAtoms::name, name);
@@ -1497,17 +1493,17 @@ HTMLInputElement::AfterSetAttr(int32_t a
       // See corresponding @max comment
       UpdateStepMismatchValidityState();
       MOZ_ASSERT(!mDoneCreating ||
                  mType != NS_FORM_INPUT_RANGE ||
                  !GetValidityState(VALIDITY_STATE_RANGE_UNDERFLOW),
                  "HTML5 spec does not allow underflow for type=range");
     } else if (aName == nsGkAtoms::dir &&
                aValue && aValue->Equals(nsGkAtoms::_auto, eIgnoreCase)) {
-      SetDirectionIfAuto(true, aNotify);
+      SetDirectionFromValue(aNotify);
     } else if (aName == nsGkAtoms::lang) {
       if (mType == NS_FORM_INPUT_NUMBER) {
         // Update the value that is displayed to the user to the new locale:
         nsAutoString value;
         GetNonFileValueInternal(value);
         nsNumberControlFrame* numberControlFrame =
           do_QueryFrame(GetPrimaryFrame());
         if (numberControlFrame) {
@@ -4861,17 +4857,19 @@ HTMLInputElement::BindToTree(nsIDocument
 
   // Add radio to document if we don't have a form already (if we do it's
   // already been added into that group)
   if (aDocument && !mForm && mType == NS_FORM_INPUT_RADIO) {
     AddedToRadioGroup();
   }
 
   // Set direction based on value if dir=auto
-  SetDirectionIfAuto(HasDirAuto(), false);
+  if (HasDirAuto()) {
+    SetDirectionFromValue(false);
+  }
 
   // An element can't suffer from value missing if it is not in a document.
   // We have to check if we suffer from that as we are now in a document.
   UpdateValueMissingValidityState();
 
   // If there is a disabled fieldset in the parent chain, the element is now
   // barred from constraint validation and can't suffer from value missing
   // (call done before).
@@ -6299,27 +6297,22 @@ HTMLInputElement::SetDefaultValueAsValue
   nsAutoString resetVal;
   GetDefaultValue(resetVal);
 
   // SetValueInternal is going to sanitize the value.
   return SetValueInternal(resetVal, nsTextEditorState::eSetValue_Internal);
 }
 
 void
-HTMLInputElement::SetDirectionIfAuto(bool aAuto, bool aNotify)
-{
-  if (aAuto) {
-    SetHasDirAuto();
-    if (IsSingleLineTextControl(true)) {
-      nsAutoString value;
-      GetValue(value, CallerType::System);
-      SetDirectionalityFromValue(this, value, aNotify);
-    }
-  } else {
-    ClearHasDirAuto();
+HTMLInputElement::SetDirectionFromValue(bool aNotify)
+{
+  if (IsSingleLineTextControl(true)) {
+    nsAutoString value;
+    GetValue(value, CallerType::System);
+    SetDirectionalityFromValue(this, value, aNotify);
   }
 }
 
 NS_IMETHODIMP
 HTMLInputElement::Reset()
 {
   // We should be able to reset all dirty flags regardless of the type.
   SetCheckedChanged(false);
@@ -7742,17 +7735,17 @@ HTMLInputElement::InitializeKeyboardEven
 NS_IMETHODIMP_(void)
 HTMLInputElement::OnValueChanged(bool aNotify, bool aWasInteractiveUserChange)
 {
   mLastValueChangeWasInteractive = aWasInteractiveUserChange;
 
   UpdateAllValidityStates(aNotify);
 
   if (HasDirAuto()) {
-    SetDirectionIfAuto(true, aNotify);
+    SetDirectionFromValue(aNotify);
   }
 
   // :placeholder-shown pseudo-class may change when the value changes.
   // However, we don't want to waste cycles if the state doesn't apply.
   if (PlaceholderApplies() &&
       HasAttr(kNameSpaceID_None, nsGkAtoms::placeholder)) {
     UpdateState(aNotify);
   }

--- a/dom/html/HTMLInputElement.h
+++ b/dom/html/HTMLInputElement.h
@@ -1124,17 +1124,17 @@ protected:
 
   /**
    * Set the current default value to the value of the input element.
    * @note You should not call this method if GetValueMode() doesn't return
    * VALUE_MODE_VALUE.
    */
   nsresult SetDefaultValueAsValue();
 
-  virtual void SetDirectionIfAuto(bool aAuto, bool aNotify);
+  void SetDirectionFromValue(bool aNotify);
 
   /**
    * Return if an element should have a specific validity UI
    * (with :-moz-ui-invalid and :-moz-ui-valid pseudo-classes).
    *
    * @return Whether the element should have a validity UI.
    */
   bool ShouldShowValidityUI() const {