Fix undefined shift in DiyFpStrtod.

third_party/WebKit/Source/wtf/dtoa/strtod.cc

 // Copyright 2010 the V8 project authors. 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
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 246 matching lines @@
         ReadDiyFp(buffer, &input, &remaining_decimals);
         // Since we may have dropped some digits the input is not accurate.
         // If remaining_decimals is different than 0 than the error is at most
         // .5 ulp (unit in the last place).
         // We don't want to deal with fractions and therefore keep a common
         // denominator.
         const int kDenominatorLog = 3;
         const int kDenominator = 1 << kDenominatorLog;
         // Move the remaining decimals into the exponent.
         exponent += remaining_decimals;
-        int error = (remaining_decimals == 0 ? 0 : kDenominator / 2);
+        int64_t error = (remaining_decimals == 0 ? 0 : kDenominator / 2);
 
         int old_e = input.e();
         input.Normalize();
         error <<= old_e - input.e();
 
         ASSERT(exponent <= PowersOfTenCache::kMaxDecimalExponent);
         if (exponent < PowersOfTenCache::kMinDecimalExponent) {
             *result = 0.0;
             return true;
         }
@@ skipping 158 matching lines @@
         if (DoubleStrtod(trimmed, exponent, &guess) ||
             DiyFpStrtod(trimmed, exponent, &guess)) {
             return guess;
         }
         return BignumStrtod(trimmed, exponent, guess);
     }
 
 }  // namespace double_conversion
 
 } // namespace WTF