Print Preview: Return or crash on failures

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 668 matching lines @@
 
 void PrintPreviewHandler::HandleGetPrivetPrinters(const base::ListValue* args) {
   std::string callback_id;
   CHECK(args->GetString(0, &callback_id));
   CHECK(!callback_id.empty());
 
   AllowJavascript();
 
   if (!PrivetPrintingEnabled()) {
     RejectJavascriptCallback(base::Value(callback_id), base::Value());
+    return;
   }
 #if BUILDFLAG(ENABLE_SERVICE_DISCOVERY)
   using local_discovery::ServiceDiscoverySharedClient;
   scoped_refptr<ServiceDiscoverySharedClient> service_discovery =
       ServiceDiscoverySharedClient::GetInstance();
   DCHECK(privet_search_callback_id_.empty());
   privet_search_callback_id_ = callback_id;
   StartPrivetLister(service_discovery);
 #endif
 }
@@ skipping 178 matching lines @@
   // before printing.
   UMA_HISTOGRAM_COUNTS("PrintPreview.RegeneratePreviewRequest.BeforePrint",
                        regenerate_preview_request_count_);
 
   AllowJavascript();
 
   std::string callback_id;
   CHECK(args->GetString(0, &callback_id));
   CHECK(!callback_id.empty());
   std::string json_str;
-  if (!args->GetString(1, &json_str))
-    RejectJavascriptCallback(base::Value(callback_id), base::Value(-1));
+  CHECK(args->GetString(1, &json_str));
 
   std::unique_ptr<base::DictionaryValue> settings =
       GetSettingsDictionary(json_str);
-  if (!settings)
+  if (!settings) {
     RejectJavascriptCallback(base::Value(callback_id), base::Value(-1));
+    return;
+  }
 
   ReportPrintSettingsStats(*settings);
 
   // Report whether the user printed a PDF or an HTML document.
   ReportPrintDocumentTypeHistogram(print_preview_ui()->source_is_modifiable() ?
                                    HTML_DOCUMENT : PDF_DOCUMENT);
 
   bool print_to_pdf = false;
   bool is_cloud_printer = false;
   bool print_with_privet = false;
@@ skipping 1018 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;
 }