Push HTTP requests to front of the queue rather than the end.

This is because we should retrieve the oldest requests from the end of
the queue.

Bug: 916420
Change-Id: I0232eb73d2c922297833a93adb22da39c91047e2
Reviewed-on: https://chromium-review.googlesource.com/c/1493339
Reviewed-by: Michael Martis <martis@chromium.org>
Commit-Queue: Rachel Wong <wrong@chromium.org>
Cr-Commit-Position: refs/heads/master@{#636681}
2 files changed