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

chrome/common/spellcheck_marker.h

 // Copyright (c) 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.
 
 #ifndef CHROME_COMMON_SPELLCHECK_MARKER_H_
 #define CHROME_COMMON_SPELLCHECK_MARKER_H_
 
 class SpellCheckMarker {
  public:
   // A predicate to test spellcheck marker validity.
   class IsValidPredicate {
    public:
     typedef SpellCheckMarker argument_type;
     explicit IsValidPredicate(size_t text_length) : text_length_(text_length) {}
     bool operator()(const SpellCheckMarker& marker) const {
       return marker.offset < text_length_;
     }
    private:
     size_t text_length_;
   };
 
   // IPC requires a default constructor.
-  SpellCheckMarker() : hash(-1), offset(-1) {}
+  SpellCheckMarker() : hash(0xFFFFFFFF), offset(static_cast<size_t>(-1)) {}
 
   SpellCheckMarker(uint32 hash, size_t offset) : hash(hash), offset(offset) {}
 
   uint32 hash;
   size_t offset;
 };
 
 #endif  // CHROME_COMMON_SPELLCHECK_MARKER_H_