Bug 1340483 - Part 3. Enable preview function only when input is marked as autofill field. r=heycam

MozReview-Commit-ID: FFqYJ3icRd7

dom/html/HTMLInputElement.cpp

@@ -1099,6 +1099,7 @@ HTMLInputElement::HTMLInputElement(already_AddRefed<mozilla::dom::NodeInfo>& aNo
   , mNumberControlSpinnerSpinsUp(false)
   , mPickerRunning(false)
   , mSelectionCached(true)
+  , mIsPreviewEnabled(false)
 {
   // We are in a type=text so we now we currenty need a nsTextEditorState.
   mInputData.mState =
@@ -2930,6 +2931,24 @@ HTMLInputElement::GetPreviewValue(nsAString& aValue)
   }
 }
 
+NS_IMETHODIMP_(void)
+HTMLInputElement::EnablePreview()
+{
+  if (mIsPreviewEnabled) {
+    return;
+  }
+
+  mIsPreviewEnabled = true;
+  // Reconstruct the frame to append an anonymous preview node
+  nsLayoutUtils::PostRestyleEvent(this, nsRestyleHint(0), nsChangeHint_ReconstructFrame);
+}
+
+NS_IMETHODIMP_(bool)
+HTMLInputElement::IsPreviewEnabled()
+{
+  return mIsPreviewEnabled;
+}
+
 void
 HTMLInputElement::GetDisplayFileName(nsAString& aValue) const
 {