Fix some clang warnings with -Wmissing-braces in base.

base/files/memory_mapped_file_win.cc

 // Copyright 2013 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/files/memory_mapped_file.h"
 
 #include "base/files/file_path.h"
 #include "base/strings/string16.h"
 #include "base/threading/thread_restrictions.h"
 
@@ skipping 14 matching lines @@
   if (!file_.IsValid())
     return false;
 
   int flags = image_ ? SEC_IMAGE | PAGE_READONLY : PAGE_READONLY;
 
   file_mapping_.Set(::CreateFileMapping(file_.GetPlatformFile(), NULL,
                                         flags, 0, 0, NULL));
   if (!file_mapping_.IsValid())
     return false;
 
-  LARGE_INTEGER map_start = {0};
+  LARGE_INTEGER map_start = {};
   SIZE_T map_size = 0;
   int32 data_offset = 0;
 
   if (region == MemoryMappedFile::Region::kWholeFile) {
     int64 file_len = file_.GetLength();
     if (file_len <= 0 || file_len > kint32max)
       return false;
     length_ = static_cast<size_t>(file_len);
   } else {
     // The region can be arbitrarily aligned. MapViewOfFile, instead, requires
@@ skipping 37 matching lines @@
   if (file_mapping_.IsValid())
     file_mapping_.Close();
   if (file_.IsValid())
     file_.Close();
 
   data_ = NULL;
   length_ = 0;
 }
 
 }  // namespace base