Reland r152781 - "Fix a history bug where a reload is given a standard load's history entry."

This reverts commit d1dc33d638f4657d4b4563de30d8f2bc089f8850.

BUG=241581

Review URL: https://chromiumcodereview.appspot.com/17519002

git-svn-id: svn://svn.chromium.org/blink/trunk@152974 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove the 'http_lock' and 'file_lock' code from webkitpy.

We used to allow running run-webkit-tests concurrently and they would
coordinate amongst themselves when running the http tests using file
locks. This was used by the Qt port on their buildbots, but it's not
clear that this was needed anywhere else.

This patch removes all of that code, and deletes the generic file lock
module we had as it was now only being used when parsing ASAN logs,
which is only needed on mac and linux (where we can just use flock).

This patch also moves starting and stopping the servers from the
layout_test_runner to the manager, where we can wait to stop the servers
until after retrying any tests. This keeps us from having to start the
servers twice if we need to retry an HTTP test. This will speed up
HTTP retries a tiny bit, but slow down the overall run-webkit-tests
execution a bit in the normal case (no HTTP retries). This tradeoff
seems worth it in order to simplify the logic overall.

R=abarth@chromium.org, ojan@chromium.org
BUG=252035

Review URL: https://chromiumcodereview.appspot.com/17320009

git-svn-id: svn://svn.chromium.org/blink/trunk@152975 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Remove extraneous assert after r152967.

Extra asserts for everyone!

TBR=esprehn@chromium.org

Review URL: https://codereview.chromium.org/17580028

git-svn-id: svn://svn.chromium.org/blink/trunk@152976 bbb929c8-8fbe-4397-9dbb-9b2b20218538