Fix more warnings on linux

Source/core/platform/graphics/WidthCache.h

 /*
  * Copyright (C) 2012 Apple Inc. All rights reserved.
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
  * 1. Redistributions of source code must retain the above copyright
  *    notice, this list of conditions and the following disclaimer.
  * 2. Redistributions in binary form must reproduce the above copyright
  *    notice, this list of conditions and the following disclaimer in the
@@ skipping 89 matching lines @@
     struct SmallStringKeyHash {
         static unsigned hash(const SmallStringKey& key) { return key.hash(); }
         static bool equal(const SmallStringKey& a, const SmallStringKey& b) { return a == b; }
         static const bool safeToCompareToEmptyOrDeleted = true; // Empty and deleted values have lengths that are not equal to any valid length.
     };
 
     struct SmallStringKeyHashTraits : WTF::SimpleClassHashTraits<SmallStringKey> {
         static const bool hasIsEmptyValueFunction = true;
         static bool isEmptyValue(const SmallStringKey& key) { return key.isHashTableEmptyValue(); }
         static const bool needsDestruction = false;
-        static const int minimumTableSize = 16;
+        static const unsigned minimumTableSize = 16;
     };
 
     friend bool operator==(const SmallStringKey&, const SmallStringKey&);
 
 public:
     WidthCache()
         : m_interval(s_maxInterval)
         , m_countdown(m_interval)
     {
     }
@@ skipping 86 matching lines @@
 inline bool operator==(const WidthCache::SmallStringKey& a, const WidthCache::SmallStringKey& b)
 {
     if (a.length() != b.length())
         return false;
     return WTF::equal(a.characters(), b.characters(), a.length());
 }
 
 } // namespace WebCore
 
 #endif // WidthCache_h