Print Preview: Use cr.sendWithPromise for getInitialSettings

chrome/browser/ui/webui/print_preview/print_preview_handler.cc

 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "chrome/browser/ui/webui/print_preview/print_preview_handler.h"
 
 #include <ctype.h>
 #include <stddef.h>
 
 #include <map>
@@ skipping 1190 matching lines @@
   if (errorCode > U_ZERO_ERROR || system != UMS_US)
     system = UMS_SI;
 
   // Getting the number formatting based on the locale and writing to
   // dictionary.
   settings->SetString(kNumberFormat, base::FormatDouble(123456.78, 2));
   settings->SetInteger(kMeasurementSystem, system);
 }
 
 void PrintPreviewHandler::HandleGetInitialSettings(
-    const base::ListValue* /*args*/) {
+    const base::ListValue* args) {
+  AllowJavascript();
+
+  std::string callback_id;
+  if (!args->GetString(0, &callback_id) || callback_id.empty()) {

[dpapad, 2017/05/17 23:59:12]

If we get in here, that would be a programmer's error, right? Can we use an
assertion CHECK or DCHECK instead? See example
https://cs.chromium.org/chromium/src/chrome/browser/ui/webui/settings/languag....

[rbpotter, 2017/05/18 17:56:30]

Done.

+    RejectJavascriptCallback(base::Value(callback_id), base::Value());
+  }
+
   // Send before SendInitialSettings() to allow cloud printer auto select.
   SendCloudPrintEnabled();
-  printer_backend_proxy()->GetDefaultPrinter(base::Bind(
-      &PrintPreviewHandler::SendInitialSettings, weak_factory_.GetWeakPtr()));
+  printer_backend_proxy()->GetDefaultPrinter(
+      base::Bind(&PrintPreviewHandler::SendInitialSettings,
+                 weak_factory_.GetWeakPtr(), callback_id));
 }
 
 void PrintPreviewHandler::HandleForceOpenNewTab(const base::ListValue* args) {
   std::string url;
   if (!args->GetString(0, &url))
     return;
   Browser* browser = chrome::FindBrowserWithWebContents(GetInitiator());
   if (!browser)
     return;
   chrome::AddSelectedTabWithURL(browser,
                                 GURL(url),
                                 ui::PAGE_TRANSITION_LINK);
 }
 
 void PrintPreviewHandler::SendInitialSettings(
+    const std::string& callback_id,
     const std::string& default_printer) {
   base::DictionaryValue initial_settings;
   initial_settings.SetString(kInitiatorTitle,
                              print_preview_ui()->initiator_title());
   initial_settings.SetBoolean(printing::kSettingPreviewModifiable,
                               print_preview_ui()->source_is_modifiable());
   initial_settings.SetString(printing::kSettingPrinterName, default_printer);
   initial_settings.SetBoolean(kDocumentHasSelection,
                               print_preview_ui()->source_has_selection());
   initial_settings.SetBoolean(printing::kSettingShouldPrintSelectionOnly,
@@ skipping 14 matching lines @@
                               chrome::IsRunningInForcedAppMode());
   if (prefs) {
     const std::string rules_str =
         prefs->GetString(prefs::kPrintPreviewDefaultDestinationSelectionRules);
     if (!rules_str.empty())
       initial_settings.SetString(kDefaultDestinationSelectionRules, rules_str);
   }
 
   if (print_preview_ui()->source_is_modifiable())
     GetNumberFormatAndMeasurementSystem(&initial_settings);
-  web_ui()->CallJavascriptFunctionUnsafe("setInitialSettings",
-                                         initial_settings);
+  ResolveJavascriptCallback(base::Value(callback_id), initial_settings);
 }
 
 void PrintPreviewHandler::ClosePreviewDialog() {
   print_preview_ui()->OnClosePrintPreviewDialog();
 }
 
 void PrintPreviewHandler::SendAccessToken(const std::string& type,
                                           const std::string& access_token) {
   VLOG(1) << "Get getAccessToken finished";
   web_ui()->CallJavascriptFunctionUnsafe(
@@ skipping 501 matching lines @@
 
 void PrintPreviewHandler::UnregisterForGaiaCookieChanges() {
   if (gaia_cookie_manager_service_)
     gaia_cookie_manager_service_->RemoveObserver(this);
 }
 
 void PrintPreviewHandler::SetPdfSavedClosureForTesting(
     const base::Closure& closure) {
   pdf_file_saved_closure_ = closure;
 }