Fix X64 Windows compilation.

Review URL: http://codereview.chromium.org/6312120

git-svn-id: http://v8.googlecode.com/svn/branches/bleeding_edge@6621 ce2b1a6d-e550-0410-aec6-3dcde31c8c00

test/cctest/test-fast-dtoa.cc

@@ -19,7 +19,7 @@ static const int kBufferSize = 100;
 
 // Removes trailing '0' digits.
 static void TrimRepresentation(Vector<char> representation) {
-  int len = strlen(representation.start());
+  int len = StrLength(representation.start());
   int i;
   for (i = len - 1; i >= 0; --i) {
     if (representation[i] != '0') break;