This reverts commit 99e6ba383f1c2963eb5f3b93c5ef243c07a8240d.

Reason for revert: Broke chromium bots that aren't in CQ and dont have proprietary codecs.

https://storage.googleapis.com/chromium-layout-test-archives/WebKit_Linux_Trusty/37231/layout-test-results/results.html

Will add feature detection to those mp4 tests and re-land

Original change's description:
> Stop using findMediaFile(...) in LayoutTests
>
> Historically, findMediaFile() helped choose the right extension based
> on what the browser could play. Chromium cannot play some proprietary
> formats (h264, aac, etc), so this check would choose the .ogv format
> in that case.
>
> But things have gotten crufty.
> 1) A long time ago we started running layout tests on builds that *do*
>    include proprietary codecs
> 2) But we lie about that to the tests via
>      media::RemoveProprietaryMediaTypesAndCodecsForTests()
>    This makes debugging tests a pain because manual execution doesn't
>    call this method and its easy to forget that the test wrapper does.
> 3) Lots of tests never bothered to call findMediaFile anway and just
>    hardcoded the use of an mp4 with proprietary codecs, which worked
>    because the method in #2 above only changes canPlayType responses,
>    it doesn't remove the actual support for proprietary codecs.
> 4) findMediaFile is about to be busted anyway because it only queries the
>    file mime type without supplying codec info. eg
>       canPlayType("video/mp4") == "maybe" -> lets use the mp4!
>    and even chromium will now "maybe" for this now that we no longer
>    consider mp4 proprietary (though codecs like h264 still are!)
>
> So this patch does the following:
>
> 1) Deletes findMediaFile() and instead hardcode use of the ogg file. This
>    maintains the existing behavior and avoids a massive rebaseline.
> 2) Delete media::RemoveProprietaryMediaTypesAndCodecsForTests(). Tests
>    and manual runs now behave the same.
> 3) Delete ancient media-can-play-* LayoutTests that just call canPlayType
>    with various codecs and are duplicated by content and chrome browser
>    tests (which is a better place for these checks)
> 4) Updates mediasource-config-change-mp4-* expectations to expect that
>    they should run and pass on *all* platforms (previously just android)
>
> There are still many tests that hard code the use of mp4 files. If we
> later desire to see LayoutTests run without proprietary codecs, someone
> can transition those tests. No one seems to mind at the moment.
>
> It is also not a goal to make LayoutTests try all the supported codecs.
> That is covered by unit/integration tests.
>
> Due to #2 above, a handful of tests in external/wpt/media-source now fail
> because they use mp4. Fixing these failures is tracked in Issue 794338.
>
> Change-Id: Ie357ae075c880b78d5ee9e95c1b7cc69d9d8a328
> BUG: 327115,746579,787575,568704,794338
> Reviewed-on: https://chromium-review.googlesource.com/807604
> Reviewed-by: Dale Curtis <dalecurtis@chromium.org>
> Reviewed-by: Peter Beverloo <peter@chromium.org>
> Commit-Queue: Chrome Cunningham <chcunningham@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#523821}

TBR=dalecurtis@chromium.org,peter@chromium.org,chcunningham@chromium.org

Change-Id: If11dd9503cfdeeed5033ddb1fc3a22466ea05d4b
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/825602
Reviewed-by: Chrome Cunningham <chcunningham@chromium.org>
Commit-Queue: Chrome Cunningham <chcunningham@chromium.org>
Cr-Commit-Position: refs/heads/master@{#523850}