Replace use of std::map with WTF's equivalent in rejected_promises.cc

Replace the use of std::map of std container with WTF::HashMap
in rejected_promises.cc.

Bug: 952716
Change-Id: I3d67ef2401369dd2ed9bbc4151e62221b160e02c
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1577230
Commit-Queue: Miyoung Shin <myid.shin@igalia.com>
Reviewed-by: Kentaro Hara <haraken@chromium.org>
Cr-Commit-Position: refs/heads/master@{#653071}
1 file changed