Add "previewing on hover" support for single-field autocomplete input

components/autofill/core/browser/autofill_popup_delegate.h

Index: components/autofill/core/browser/autofill_popup_delegate.h
diff --git a/components/autofill/core/browser/autofill_popup_delegate.h b/components/autofill/core/browser/autofill_popup_delegate.h
index dec139cfb83cebfce27aad03389cb996b28cb722..1c224be7c34720ab3a810faae706840a7f8a1c11 100644
--- a/components/autofill/core/browser/autofill_popup_delegate.h
+++ b/components/autofill/core/browser/autofill_popup_delegate.h
@@ -31,6 +31,10 @@ class AutofillPopupDelegate {
   // temporarily selected (e.g., hovered).
   virtual void DidSelectSuggestion(int identifier) = 0;
 
+  // Called when the Autocomplete suggestion has been temporarily selected
+  // (e.g., hovered).
+  virtual void DidSelectAutocompleteSuggestion(const base::string16& value) = 0;
+
   // Inform the delegate that a row in the popup has been chosen.
   virtual void DidAcceptSuggestion(const base::string16& value,
                                    int identifier) = 0;
@@ -41,6 +45,10 @@ class AutofillPopupDelegate {
 
   // Informs the delegate that the Autofill previewed form should be cleared.
   virtual void ClearPreviewedForm() = 0;
+
+  // Informs the delegate that the Autocomplete previewed field should be
+  // cleared.
+  virtual void ClearAutocompletePreviewedField() = 0;
 };
 
 }  // namespace autofill