GitLab

Test handshake throttling from layout tests. This involves adding a
test-specific throttle, content::TestWebSocketHandshakeThrottle, which
is used when the --run-layout-tests option is supplied. It looks for a
content-shell-websocket-delay-ms query parameter in the WebSocket URL
and applies the specified delay if it exists. As a result it does not
interfere with other tests.

Includes a regression test for crbug.com/786776. This verifies that a
message sent by the server is delivered even when the open is delayed by
throttling.

BUG=786776

Change-Id: If8b2be86ac617d037bc1ee0059512b5d950a313d
Reviewed-on: https://chromium-review.googlesource.com/867806
Commit-Queue: Adam Rice <ricea@chromium.org>
Reviewed-by: Peter Beverloo <peter@chromium.org>
Reviewed-by: Takeshi Yoshino <tyoshino@chromium.org>
Cr-Commit-Position: refs/heads/master@{#532329}