GitLab

Avoid potential unnecessary copies by using emplace consistently.

No intended functional changes.

Bug: 995605
Change-Id: I4e937338a05e6f7322d2813f2f633f0037cd4b67
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/1761649Reviewed-by: Scott Violet <sky@chromium.org>
Commit-Queue: Darwin Huang <huangdarwin@chromium.org>
Cr-Commit-Position: refs/heads/master@{#688612}