Builder: "WebKit Win7 (dbg)"

The last 6 builds have failed webkit_tests:
https://uberchromegw.corp.google.com/i/chromium.webkit/builders/WebKit%20Win7%20%28dbg%29

This is not just one consistent failure, this is multiple flaky failures in different layout tests in succession, which just made it look like a consistent failure.

The failing tests include:
* external/wpt/domxpath/xml_xpath_runner.html
* external/wpt/html/semantics/document-metadata/the-meta-element/pragma-directives/attr-meta-http-equiv-refresh/parsing.html
* external/wpt/html/syntax/parsing/html5lib_tests16.html?run_type=uri
* external/wpt/workers/Worker_terminate_event_queue.htm
* external/wpt/html/semantics/tabular-data/processing-model-1/span-limits.html
* fast/events/message-port-start-and-close-different-microtask.html
* media/controls/video-enter-exit-fullscreen-without-hovering-doesnt-show-controls.html
* virtual/new-remote-playback-pipeline/media/controls/video-enter-exit-fullscreen-without-hovering-doesnt-show-controls.html