GitLab

This was already the intent of the method but it incorrectly returned
false if there were sent messages but ProcessMessageHelper(msg)
returned false (i.e. |msg| was kMsgHaveWork and there were no others).

Extracted from https://chromium-review.googlesource.com/c/chromium/src/+/2185757/2

R=fdoray@chromium.org

Bug: 1075960
Change-Id: I3a60b01598b15f3deea5aabd83112cf2ace5cabb
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2185831
Commit-Queue: Gabriel Charette <gab@chromium.org>
Auto-Submit: Gabriel Charette <gab@chromium.org>
Reviewed-by: François Doray <fdoray@chromium.org>
Cr-Commit-Position: refs/heads/master@{#768509}