Revert "Don't trigger end of track when starting a new disabled track"

This reverts commit 447c696aaf19064a79d7bc894ce4a0aa3422c69c.

Reason for revert: Introduces a regression. See https://crbug.com/813243

Original change's description:
> Don't trigger end of track when starting a new disabled track
>
> Fix reporting a size of 2x2 on the video element during the loading
> phase.
>
> Bug: 684288
> Change-Id: Id4adceefaf4c3df57a1ba41fd285862d72792b1a
> Reviewed-on: https://chromium-review.googlesource.com/806215
> Commit-Queue: Florent Castelli <orphis@chromium.org>
> Commit-Queue: Guido Urdaneta <guidou@chromium.org>
> Reviewed-by: Guido Urdaneta <guidou@chromium.org>
> Cr-Commit-Position: refs/heads/master@{#523152}

TBR=guidou@chromium.org, orphis@chromium.org


(cherry picked from commit d1f07e92571d6a2db9ee116c267c2963f7b091ba)

Bug: 684288, 813243
Change-Id: I60bc092c23d1840a9c7e95b4b1d8d02c52c6fb46
Reviewed-on: https://chromium-review.googlesource.com/924190
Commit-Queue: Guido Urdaneta <guidou@chromium.org>
Reviewed-by: Guido Urdaneta <guidou@chromium.org>
Cr-Original-Commit-Position: refs/heads/master@{#537675}
Reviewed-on: https://chromium-review.googlesource.com/928768
Cr-Commit-Position: refs/branch-heads/3325@{#547}
Cr-Branched-From: bc084a8b5afa3744a74927344e304c02ae54189f-refs/heads/master@{#530369}
3 files changed