Update JSONReader to take base::StringPiece instead of std::string

base/json/json_reader.h

 // 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.
 //
 // A JSON parser.  Converts strings of JSON into a Value object (see
 // base/values.h).
 // http://www.ietf.org/rfc/rfc4627.txt?number=4627
 //
 // Known limitations/deviations from the RFC:
 // - Only knows how to parse ints within the range of a signed 32 bit int and
@@ skipping 15 matching lines @@
 // TODO(tc): Add an option to disable comment stripping
 
 #ifndef BASE_JSON_JSON_READER_H_
 #define BASE_JSON_JSON_READER_H_
 #pragma once
 
 #include <string>
 
 #include "base/base_export.h"
 #include "base/basictypes.h"
+#include "base/string_piece.h"
 
 // Chromium and Chromium OS check out gtest to different places, so we're
 // unable to compile on both if we include gtest_prod.h here.  Instead, include
 // its only contents -- this will need to be updated if the macro ever changes.
 #define FRIEND_TEST(test_case_name, test_name)\
 friend class test_case_name##_##test_name##_Test
 
 #define FRIEND_TEST_ALL_PREFIXES(test_case_name, test_name) \
   FRIEND_TEST(test_case_name, test_name); \
   FRIEND_TEST(test_case_name, DISABLED_##test_name); \
@@ skipping 68 matching lines @@
   static const char* kUnexpectedDataAfterRoot;
   static const char* kUnsupportedEncoding;
   static const char* kUnquotedDictionaryKey;
 
   JSONReader();
 
   // Reads and parses |json|, returning a Value. The caller owns the returned
   // instance. If |json| is not a properly formed JSON string, returns NULL.
   // If |allow_trailing_comma| is true, we will ignore trailing commas in
   // objects and arrays even though this goes against the RFC.
-  static Value* Read(const std::string& json, bool allow_trailing_comma);
+  static Value* Read(const StringPiece& json, bool allow_trailing_comma);
 
   // Reads and parses |json| like Read(). |error_code_out| and |error_msg_out|
   // are optional. If specified and NULL is returned, they will be populated
   // an error code and a formatted error message (including error location if
   // appropriate). Otherwise, they will be unmodified.
-  static Value* ReadAndReturnError(const std::string& json,
+  static Value* ReadAndReturnError(const StringPiece& json,
                                    bool allow_trailing_comma,
                                    int* error_code_out,
                                    std::string* error_msg_out);
 
   // Converts a JSON parse error code into a human readable message.
   // Returns an empty string if error_code is JSON_NO_ERROR.
   static std::string ErrorCodeToString(JsonParseError error_code);
 
   // Returns the error code if the last call to JsonToValue() failed.
   // Returns JSON_NO_ERROR otherwise.
   JsonParseError error_code() const { return error_code_; }
 
   // Converts error_code_ to a human-readable string, including line and column
   // numbers if appropriate.
   std::string GetErrorMessage() const;
 
   // Reads and parses |json|, returning a Value. The caller owns the returned
   // instance. If |json| is not a properly formed JSON string, returns NULL and
   // a detailed error can be retrieved from |error_message()|.
   // If |check_root| is true, we require that the root object be an object or
   // array. Otherwise, it can be any valid JSON type.
   // If |allow_trailing_comma| is true, we will ignore trailing commas in
   // objects and arrays even though this goes against the RFC.
-  Value* JsonToValue(const std::string& json, bool check_root,
+  Value* JsonToValue(const StringPiece& json, bool check_root,
                      bool allow_trailing_comma);
 
  private:
   FRIEND_TEST_ALL_PREFIXES(JSONReaderTest, Reading);
   FRIEND_TEST_ALL_PREFIXES(JSONReaderTest, ErrorMessages);
 
   static std::string FormatErrorMessage(int line, int column,
                                         const std::string& description);
 
   // Recursively build Value.  Returns NULL if we don't have a valid JSON
@@ skipping 69 matching lines @@
   JsonParseError error_code_;
   int error_line_;
   int error_col_;
 
   DISALLOW_COPY_AND_ASSIGN(JSONReader);
 };
 
 }  // namespace base
 
 #endif  // BASE_JSON_JSON_READER_H_