Move hash.h/cc from net/disk_cache to base.

base/hash.cc

 // From http://www.azillionmonkeys.com/qed/hash.html
 
-#include "net/disk_cache/hash.h"
+#include "base/hash.h"
 
 typedef uint32 uint32_t;
 typedef uint16 uint16_t;
 
-namespace disk_cache {
+namespace base {
 
 #undef get16bits
 #if (defined(__GNUC__) && defined(__i386__)) || defined(__WATCOMC__) \
   || defined(_MSC_VER) || defined (__BORLANDC__) || defined (__TURBOC__)
 #define get16bits(d) (*((const uint16_t *) (d)))
 #endif
 
 #if !defined (get16bits)
 #define get16bits(d) ((((uint32_t)(((const uint8_t *)(d))[1])) << 8)\
                        +(uint32_t)(((const uint8_t *)(d))[0]) )
@@ skipping 44 matching lines @@
   hash ^= hash << 3;
   hash += hash >> 5;
   hash ^= hash << 4;
   hash += hash >> 17;
   hash ^= hash << 25;
   hash += hash >> 6;
 
   return hash;
 }
 
-}  // namespace disk_cache
+}  // namespace base