Move all static constants in dtoa/cached-powers.* to .rodata section

Source/wtf/dtoa/cached-powers.h

 // 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 21 matching lines @@
 
 namespace WTF {
 
 namespace double_conversion {
 
     class PowersOfTenCache {
     public:
 
         // Not all powers of ten are cached. The decimal exponent of two neighboring
         // cached numbers will differ by kDecimalExponentDistance.
-        static int kDecimalExponentDistance;
+        static const int kDecimalExponentDistance;
 
-        static int kMinDecimalExponent;
-        static int kMaxDecimalExponent;
+        static const int kMinDecimalExponent;
+        static const int kMaxDecimalExponent;
 
         // Returns a cached power-of-ten with a binary exponent in the range
         // [min_exponent; max_exponent] (boundaries included).
         static void GetCachedPowerForBinaryExponentRange(int min_exponent,
                                                          int max_exponent,
                                                          DiyFp* power,
                                                          int* decimal_exponent);
 
         // Returns a cached power of ten x ~= 10^k such that
         //   k <= decimal_exponent < k + kCachedPowersDecimalDistance.
         // The given decimal_exponent must satisfy
         //   kMinDecimalExponent <= requested_exponent, and
         //   requested_exponent < kMaxDecimalExponent + kDecimalExponentDistance.
         static void GetCachedPowerForDecimalExponent(int requested_exponent,
                                                      DiyFp* power,
                                                      int* found_exponent);
     };
-
-    // Initializes the table of cached powers used by the dtoa algorithm.
-    // This needs to be called when JSC is being initialized.
-    void initialize();
-
 }  // namespace double_conversion
 
 } // namespace WTF
 
 #endif  // DOUBLE_CONVERSION_CACHED_POWERS_H_