I have a revert of the test in CQ. I will work on a reland next week.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/b219ac43dfc572c386868eae614f957f7ee812b1

commit b219ac43dfc572c386868eae614f957f7ee812b1
Author: Ehsan Karamad <ekaramad@chromium.org>
Date: Thu Sep 13 23:13:05 2018

Revert "Make 'web_view_browsertest.cc' BrowserPlugin-free"

This reverts commit d3358a99e012a585ce80ff0f4416930fe96978ba.

Reason for revert: The test seems to be very flaky.

Bug:  883965 

Original change's description:
> Make 'web_view_browsertest.cc' BrowserPlugin-free
> 
> This CL removes and converts the last remaining BrowserPlugin-based test
> to chrome_mime_handler_view_browsertest.cc (the new test uses a
> MimeHandlerViewGuest).
> 
> Bug: 553069, 330264
> Change-Id: I487fbd47ca0c989e746d087c72fe396f9e9ac867
> Reviewed-on: https://chromium-review.googlesource.com/1221693
> Reviewed-by: James MacLean <wjmaclean@chromium.org>
> Commit-Queue: Ehsan Karamad <ekaramad@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#591115}

TBR=ekaramad@chromium.org,wjmaclean@chromium.org

Change-Id: I60e4bc6872645cb1be4de70d19f41c1c4e6e51b6
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Bug: 553069, 330264
Reviewed-on: https://chromium-review.googlesource.com/1226202
Reviewed-by: Ehsan Karamad <ekaramad@chromium.org>
Commit-Queue: Ehsan Karamad <ekaramad@chromium.org>
Cr-Commit-Position: refs/heads/master@{#591198}
[modify] https://crrev.com/b219ac43dfc572c386868eae614f957f7ee812b1/chrome/browser/apps/guest_view/web_view_browsertest.cc
[modify] https://crrev.com/b219ac43dfc572c386868eae614f957f7ee812b1/chrome/browser/guest_view/mime_handler_view/chrome_mime_handler_view_browsertest.cc
[modify] https://crrev.com/b219ac43dfc572c386868eae614f957f7ee812b1/chrome/test/data/extensions/api_test/mime_handler_view/test_embedded.html
[modify] https://crrev.com/b219ac43dfc572c386868eae614f957f7ee812b1/testing/buildbot/filters/chromeos.mash.fyi.browser_tests.filter
[modify] https://crrev.com/b219ac43dfc572c386868eae614f957f7ee812b1/testing/buildbot/filters/chromeos.single_process_mash.browser_tests.filter

Marking as fixed since the CL is reverted.