We should show the download button if there is a currentSrc(). I was expecting this to happen without even preloading. Needs investigation.

+dahlke@

A side effect of this is that we will show a download button even if the file is a 404. I don't think it's a real problem but FYI :) (we should make sure the download button gets removed as soon as we preload and have more info)

Thanks for the heads up on the behavior. I agree that we should do this despite the risks.

The following revision refers to this bug:
  https://chromium.googlesource.com/chromium/src.git/+/94aeb8cb883faee716cca33b7601df68a2d8c09c

commit 94aeb8cb883faee716cca33b7601df68a2d8c09c
Author: steimel <steimel@chromium.org>
Date: Tue Mar 07 17:22:50 2017

Show download button even when preload=none

Currently, the media controls are not reset after the currentSrc of the
video is set. This CL adds a reset call so that the download button is
displayed, along with a corresponding layout test.

BUG= 665152 

Review-Url: https://codereview.chromium.org/2728193003
Cr-Commit-Position: refs/heads/master@{#455112}

[add] https://crrev.com/94aeb8cb883faee716cca33b7601df68a2d8c09c/third_party/WebKit/LayoutTests/media/controls/download-button-displays-with-preload-none.html
[modify] https://crrev.com/94aeb8cb883faee716cca33b7601df68a2d8c09c/third_party/WebKit/Source/core/html/shadow/MediaControlElements.cpp
[modify] https://crrev.com/94aeb8cb883faee716cca33b7601df68a2d8c09c/third_party/WebKit/Source/core/html/shadow/MediaControls.cpp
[modify] https://crrev.com/94aeb8cb883faee716cca33b7601df68a2d8c09c/third_party/WebKit/Source/core/html/shadow/MediaControlsTest.cpp