Code problems detected by cppcheck

Source/platform/Decimal.cpp

 /*
  * Copyright (C) 2012 Google 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:
  *
  *     * Redistributions of source code must retain the above copyright
  * notice, this list of conditions and the following disclaimer.
  *     * Redistributions in binary form must reproduce the above
@@ skipping 122 matching lines @@
     UInt128& operator/=(uint32_t);
 
     uint64_t high() const { return m_high; }
     uint64_t low() const { return m_low; }
 
     static UInt128 multiply(uint64_t u, uint64_t v) { return UInt128(u * v, multiplyHigh(u, v)); }
 
 private:
     static uint32_t highUInt32(uint64_t x) { return static_cast<uint32_t>(x >> 32); }
     static uint32_t lowUInt32(uint64_t x) { return static_cast<uint32_t>(x & ((static_cast<uint64_t>(1) << 32) - 1)); }
-    bool isZero() const { return !m_low && !m_high; }
     static uint64_t makeUInt64(uint32_t low, uint32_t high) { return low | (static_cast<uint64_t>(high) << 32); }
 
     static uint64_t multiplyHigh(uint64_t, uint64_t);
 
     uint64_t m_high;
     uint64_t m_low;
 };
 
 UInt128& UInt128::operator/=(const uint32_t divisor)
 {
@@ skipping 864 matching lines @@
     }
     return builder.toString();
 }
 
 Decimal Decimal::zero(Sign sign)
 {
     return Decimal(EncodedData(sign, EncodedData::ClassZero));
 }
 
 } // namespace WebCore