Linux: fix build with system zlib.

chrome/common/zip_reader.h

 // 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.
 
 #ifndef CHROME_COMMON_ZIP_READER_H_
 #define CHROME_COMMON_ZIP_READER_H_
 
 #include <string>
 
 #include "base/basictypes.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/time.h"
+
+#if defined(USE_SYSTEM_MINIZIP)
+#include <minizip/unzip.h>
+#else
 #include "third_party/zlib/contrib/minizip/unzip.h"
+#endif
 
 namespace zip {
 
 // This class is used for reading zip files. A typical use case of this
 // class is to scan entries in a zip file and extract them. The code will
 // look like:
 //
 //   ZipReader reader;
 //   reader.Open(zip_file_path);
 //   while (reader.HasMore()) {
@@ skipping 137 matching lines @@
   int num_entries_;
   bool reached_end_;
   scoped_ptr<EntryInfo> current_entry_info_;
 
   DISALLOW_COPY_AND_ASSIGN(ZipReader);
 };
 
 }  // namespace zip
 
 #endif  // CHROME_COMMON_ZIP_READER_H_