commit 429b5ee96832287dd7c0747e6115227ac2447b31
author yuzus <yuzus@chromium.org> Mon Feb 01 10:22:30 2016
committer Commit bot <commit-bot@chromium.org> Mon Feb 01 10:23:19 2016
tree 1643ef3904e33948d0334aedbb9db7133f0b6491
parent 887807308ddbcae3d56962a0abcc79ef01d51275

Make HTMLSlotElement.distributedNodeNextTo & distributedNodePreviousTo faster

Currently distributedNodeNextTo & distributedNodePreviousTo are calculated using vector (O(N)). This CL makes this calculation O(1) by introducing a hashmap.
According to Performance Test, the calculation became 7.7% faster, in case of N=1000. (N being the number of distributed nodes)

With this CL:    avg 79094.69485003888 runs/s
Without this CL: avg 73466.4783609413  runs/s

BUG=531990

Review URL: https://codereview.chromium.org/1611413005

Cr-Commit-Position: refs/heads/master@{#372632}