Coverity: Initialize a member variable.

content/browser/histogram_message_filter.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.
 
 #ifndef CONTENT_BROWSER_HISTOGRAM_MESSAGE_FILTER_H_
 #define CONTENT_BROWSER_HISTOGRAM_MESSAGE_FILTER_H_
 
 #include <string>
 #include <vector>
 
@@ skipping 14 matching lines @@
   virtual bool OnMessageReceived(const IPC::Message& message,
                                  bool* message_was_ok) OVERRIDE;
 
  private:
   virtual ~HistogramMessageFilter();
 
   // Message handlers.
   void OnChildHistogramData(int sequence_number,
                             const std::vector<std::string>& pickled_histograms);
 
-  ProcessType process_type_;
-
   DISALLOW_COPY_AND_ASSIGN(HistogramMessageFilter);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_HISTOGRAM_MESSAGE_FILTER_H_