Stephen Adams
5923966da3
Assigning to __proto__ is a fast way to stitch together a number of object literals into a prototype chain without copying all the properties. Unfortunately this leads to very slow execution on Firefox (and jsshell). So now we feature-detect Chrome (and d8) since that is the only browser we know currently can use the 'fast' startup path without penalizing subsequent performance. This speeds up some jsshell benchmarks by 30%. R=het@google.com Review URL: https://codereview.chromium.org/2180533002 .