gn win: Fix potentially uninitialized variable warning in zip_internal

third_party/zlib/google/zip_internal.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 "third_party/zlib/google/zip_internal.h"
 
 #include <algorithm>
 
 #include "base/file_util.h"
 #include "base/logging.h"
@@ skipping 19 matching lines @@
 #if defined(OS_WIN)
 typedef struct {
   HANDLE hf;
   int error;
 } WIN32FILE_IOWIN;
 
 // This function is derived from third_party/minizip/iowin32.c.
 // Its only difference is that it treats the char* as UTF8 and
 // uses the Unicode version of CreateFile.
 void* ZipOpenFunc(void *opaque, const char* filename, int mode) {
-  DWORD desired_access, creation_disposition;
-  DWORD share_mode, flags_and_attributes;
+  DWORD desired_access = 0, creation_disposition = 0;
+  DWORD share_mode = 0, flags_and_attributes = 0;
   HANDLE file = 0;
   void* ret = NULL;
 
-  desired_access = share_mode = flags_and_attributes = 0;
-
   if ((mode & ZLIB_FILEFUNC_MODE_READWRITEFILTER) == ZLIB_FILEFUNC_MODE_READ) {
     desired_access = GENERIC_READ;
     creation_disposition = OPEN_EXISTING;
     share_mode = FILE_SHARE_READ;
   } else if (mode & ZLIB_FILEFUNC_MODE_EXISTING) {
     desired_access = GENERIC_WRITE | GENERIC_READ;
     creation_disposition = OPEN_EXISTING;
   } else if (mode & ZLIB_FILEFUNC_MODE_CREATE) {
     desired_access = GENERIC_WRITE | GENERIC_READ;
     creation_disposition = CREATE_ALWAYS;
@@ skipping 314 matching lines @@
                     0,  // versionMadeBy
                     LANGUAGE_ENCODING_FLAG)) {  // flagBase
     DLOG(ERROR) << "Could not open zip file entry " << str_path;
     return false;
   }
   return true;
 }
 
 }  // namespace internal
 }  // namespace zip