Fix some grammatical errors in base/

base/json/json_reader.cc

 // Copyright (c) 2011 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 "base/json/json_reader.h"
 
 #include "base/float_util.h"
 #include "base/logging.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/stringprintf.h"
@@ skipping 480 matching lines @@
         case 'u':
           decoded_str.push_back((HexDigitToInt(*(token.begin + i + 1)) << 12 ) +
                                 (HexDigitToInt(*(token.begin + i + 2)) << 8) +
                                 (HexDigitToInt(*(token.begin + i + 3)) << 4) +
                                 HexDigitToInt(*(token.begin + i + 4)));
           i += 4;
           break;
 
         default:
           // We should only have valid strings at this point.  If not,
-          // ParseStringToken didn't do it's job.
+          // ParseStringToken didn't do its job.
           NOTREACHED();
           return NULL;
       }
     } else {
       // Not escaped
       decoded_str.push_back(c);
     }
   }
   return Value::CreateStringValue(WideToUTF16Hack(decoded_str));
 }
@@ skipping 145 matching lines @@
       ++column_number;
     }
   }
 
   error_line_ = line_number;
   error_col_ = column_number;
   error_code_ = error;
 }
 
 }  // namespace base