app_list: Add web store search.

chrome/browser/safe_json_parser.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 CHROME_BROWSER_SAFE_JSON_PARSER_H_
+#define CHROME_BROWSER_SAFE_JSON_PARSER_H_
+
+#include <string>
+
+#include "base/basictypes.h"
+#include "base/callback.h"
+#include "base/memory/scoped_ptr.h"
+#include "content/public/browser/utility_process_host_client.h"
+
+namespace base {
+class ListValue;
+class Value;
+}
+
+namespace IPC {
+class Message;
+}
+
+// Helper class to parse given JSON safely via utility process.
+class SafeJsonParser : public content::UtilityProcessHostClient {
+ public:
+  typedef base::Callback<void(scoped_ptr<base::Value>)> SuccessCallback;
+  typedef base::Callback<void(const std::string&)> ErrorCallback;
+
+  SafeJsonParser(const std::string& unsafe_json,

[James Cook, 2013/05/20 14:39:34]

nit: Maybe comment on memory lifetime - I presume it deletes itself after either
success or failure?  Before or after calling the callback?

[xiyuan, 2013/05/20 16:56:31]

Updated the class comment to document the lifetime.

+                 const SuccessCallback& success_callback,
+                 const ErrorCallback& error_callback);
+
+  void Start();
+
+ private:
+  virtual ~SafeJsonParser();
+
+  void StartWorkOnIOThread();
+
+  void OnJSONParseSucceeded(const base::ListValue& wrapper);
+  void OnJSONParseFailed(const std::string& error_message);
+
+  void ReportResults();
+  void ReportResultOnUIThread();
+
+  // Implementing pieces of the UtilityProcessHostClient interface.
+  virtual bool OnMessageReceived(const IPC::Message& message) OVERRIDE;
+
+  const std::string unsafe_json_;
+  SuccessCallback success_callback_;
+  ErrorCallback error_callback_;
+
+  scoped_ptr<base::Value> parsed_json_;
+  std::string error_;
+
+  DISALLOW_COPY_AND_ASSIGN(SafeJsonParser);
+};
+
+#endif  // CHROME_BROWSER_SAFE_JSON_PARSER_H_