Http Bad: Add "Learn more" sublabel to warning message and make it clickable

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 e5a94d422bdafe61531dcbb04ed985844b368aac..9c8c7c139cc97edcb7b84e2d9bbbe0beeb90ce5f 100644
--- a/components/autofill/core/browser/autofill_external_delegate.cc
+++ b/components/autofill/core/browser/autofill_external_delegate.cc
@@ -225,6 +225,8 @@ void AutofillExternalDelegate::DidAcceptSuggestion(const base::string16& value,
         &AutofillExternalDelegate::OnCreditCardScanned, GetWeakPtr()));
   } else if (identifier == POPUP_ITEM_ID_CREDIT_CARD_SIGNIN_PROMO) {
     manager_->client()->StartSigninFlow();
+  } else if (identifier == POPUP_ITEM_ID_HTTP_NOT_SECURE_WARNING_MESSAGE) {
+    manager_->client()->ShowHttpNotSecureExplanation();
   } else {
     if (identifier > 0)  // Denotes an Autofill suggestion.
       AutofillMetrics::LogAutofillSuggestionAcceptedIndex(position);