Fix XMLWriter crash

chrome/common/libxml_utils.cc

-// Copyright (c) 2006-2008 The Chromium Authors. All rights reserved.
+// Copyright (c) 2006-2009 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/common/libxml_utils.h"
 
 #include "base/compiler_specific.h"
 #include "base/logging.h"
 #include "base/string_util.h"
 
 #include "libxml/xmlreader.h"
@@ skipping 101 matching lines @@
       continue;
     }
   } while (Read());
   return false;
 }
 
 
 // XmlWriter functions
 
 XmlWriter::XmlWriter() :
-    writer_(NULL) {}
+    writer_(NULL),
+    buffer_(NULL) {}
 
 XmlWriter::~XmlWriter() {
   if (writer_)
     xmlFreeTextWriter(writer_);
   if (buffer_)
     xmlBufferFree(buffer_);
 }
 
 void XmlWriter::StartWriting() {
   buffer_ = xmlBufferCreate();
   writer_ = xmlNewTextWriterMemory(buffer_, 0);
   xmlTextWriterSetIndent(writer_, 1);
   xmlTextWriterStartDocument(writer_, NULL, NULL, NULL);
 }
 
 void XmlWriter::StopWriting() {
   xmlTextWriterEndDocument(writer_);
   xmlFreeTextWriter(writer_);
   writer_ = NULL;
 }