Re-land: Convert the utility process JSON parser into a Mojo service.

components/safe_json/safe_json_parser_impl.h

 // Copyright 2013 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.
 
 #ifndef COMPONENTS_SAFE_JSON_SAFE_JSON_PARSER_IMPL_H_
 #define COMPONENTS_SAFE_JSON_SAFE_JSON_PARSER_IMPL_H_
 
 #include <memory>
 #include <string>
 
 #include "base/macros.h"
 #include "base/memory/ref_counted.h"
+#include "base/memory/weak_ptr.h"
+#include "base/threading/thread_checker.h"
+#include "components/safe_json/public/interfaces/safe_json.mojom.h"
 #include "components/safe_json/safe_json_parser.h"
 #include "content/public/browser/utility_process_host_client.h"
 
 namespace base {
 class ListValue;
 class SequencedTaskRunner;
 class Value;
 }
 
+namespace content {
+class UtilityProcessHost;
+}
+
 namespace IPC {
 class Message;
 }
 
 namespace safe_json {
 
 class SafeJsonParserImpl : public content::UtilityProcessHostClient,
                            public SafeJsonParser {
  public:
   SafeJsonParserImpl(const std::string& unsafe_json,
                      const SuccessCallback& success_callback,
                      const ErrorCallback& error_callback);
 
  private:
   ~SafeJsonParserImpl() override;
 
   void StartWorkOnIOThread();
 
-  void OnJSONParseSucceeded(const base::ListValue& wrapper);
-  void OnJSONParseFailed(const std::string& error_message);
-
   void ReportResults();
   void ReportResultsOnOriginThread();
 
   // Implementing pieces of the UtilityProcessHostClient interface.
   bool OnMessageReceived(const IPC::Message& message) override;
 
   // SafeJsonParser implementation.
   void Start() override;
 
+  // mojom::SafeJsonParser::Parse callback.
+  void OnParseDone(const base::ListValue& wrapper, mojo::String error);
+
   const std::string unsafe_json_;
   SuccessCallback success_callback_;
   ErrorCallback error_callback_;
   scoped_refptr<base::SequencedTaskRunner> caller_task_runner_;
 
   std::unique_ptr<base::Value> parsed_json_;
   std::string error_;
 
+  base::WeakPtr<content::UtilityProcessHost> utility_process_host_;
+
+  mojom::SafeJsonParserPtr service_;
+
+  // To ensure the UtilityProcessHost and Mojo service are only accessed on the
+  // IO thread.
+  base::ThreadChecker io_thread_checker_;
+
   DISALLOW_COPY_AND_ASSIGN(SafeJsonParserImpl);
 };
 
 }  // namespace safe_json
 
 #endif  // COMPONENTS_SAFE_JSON_SAFE_JSON_PARSER_IMPL_H_