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

components/autofill/core/browser/autofill_external_delegate.cc

Index: components/autofill/core/browser/autofill_external_delegate.cc
diff --git a/components/autofill/core/browser/autofill_external_delegate.cc b/components/autofill/core/browser/autofill_external_delegate.cc
index c4367567ff274c7801e20dea6ef5f0dd89111e21..0fb86c6d14eefad318196c0a40de1c4802982f65 100644
--- a/components/autofill/core/browser/autofill_external_delegate.cc
+++ b/components/autofill/core/browser/autofill_external_delegate.cc
@@ -13,6 +13,7 @@
 #include "ui/base/l10n/l10n_util.h"
 
 using blink::WebAutofillClient;
+using base::ASCIIToUTF16;
 
 namespace autofill {
 
@@ -172,6 +173,15 @@ void AutofillExternalDelegate::DidSelectSuggestion(int identifier) {
     FillAutofillFormData(identifier, true);
 }
 
+void AutofillExternalDelegate::DidSelectAutocompleteSuggestion(
+    const base::string16& value) {
+  ClearPreviewedForm();
+  ClearAutocompletePreviewedField();
+
+  // Preview the data if it is in an AutoComplete field.
+  autofill_driver_->RendererShouldSetNodeText(value);
+}
+
 void AutofillExternalDelegate::DidAcceptSuggestion(const base::string16& value,
                                                    int identifier) {
   if (identifier == WebAutofillClient::MenuItemIDAutofillOptions) {
@@ -216,6 +226,10 @@ void AutofillExternalDelegate::ClearPreviewedForm() {
   autofill_driver_->RendererShouldClearPreviewedForm();
 }
 
+void AutofillExternalDelegate::ClearAutocompletePreviewedField() {
+  autofill_driver_->RendererShouldSetNodeText(ASCIIToUTF16(""));
+}
+
 void AutofillExternalDelegate::Reset() {
   autofill_manager_->delegate()->HideAutofillPopup();