Fixes for re-enabling more MSVC level 4 warnings: chrome/browser/ edition

chrome/browser/safe_browsing/safe_browsing_store_file.cc

 // 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.
 
 #include "chrome/browser/safe_browsing/safe_browsing_store_file.h"
 
 #include "base/file_util.h"
 #include "base/files/scoped_file.h"
 #include "base/md5.h"
 #include "base/metrics/histogram.h"
@@ skipping 31 matching lines @@
 // Prevent excessive sharding by setting a lower limit on the shard stride.
 // Smaller values should work fine, but very small values will probably lead to
 // poor performance.  Shard stride is indirectly related to
 // |kUpdateStorageBytes|, setting that very small will bump against this.
 const uint32 kMinShardStride = 1 << 24;
 
 // Strides over the entire SBPrefix space.
 const uint64 kMaxShardStride = 1ULL << 32;
 
 // Maximum SBPrefix value.
-const SBPrefix kMaxSBPrefix = ~0;
+const SBPrefix kMaxSBPrefix = 0xFFFFFFFF;
 
 // Header at the front of the main database file.
 struct FileHeaderV8 {
   int32 magic, version;
   uint32 add_chunk_count, sub_chunk_count;
   uint32 shard_stride;
   // TODO(shess): Is this where 64-bit will bite me?  Perhaps write a
   // specialized read/write?
 };
 
@@ skipping 898 matching lines @@
   // input file.  |out_stride| will be derived from an estimate of the resulting
   // file's size.  |process_stride| will be the max of both.
   uint64 in_stride = kMaxShardStride;
   uint64 out_stride = kMaxShardStride;
   uint64 process_stride = 0;
 
   // The header info is only used later if |!empty_|.  The v8 read loop only
   // needs |in_stride|, while v7 needs to refer to header information.
   base::MD5Context in_context;
   int version = kInvalidVersion;
-  FileHeader header;
+  FileHeader header = {{0}};
 
   if (!empty_) {
     DCHECK(file_.get());
 
     version = ReadAndVerifyHeader(filename_, &header,
                                   &add_chunks_cache_, &sub_chunks_cache_,
                                   file_.get(), &in_context);
     if (version == kInvalidVersion)
       return OnCorruptDatabase();
 
@@ skipping 255 matching lines @@
   // With SQLite support gone, one way to get to this code is if the
   // existing file is a SQLite file.  Make sure the journal file is
   // also removed.
   const base::FilePath journal_filename(
       basename.value() + FILE_PATH_LITERAL("-journal"));
   if (base::PathExists(journal_filename))
     base::DeleteFile(journal_filename, false);
 
   return true;
 }