[Autoplay] Disable autoplay for media stream

Disable autoplay by default for media streams.

BUG=873768

Change-Id: I11f8c3df295ae6ff4f71fce2eb2b3ebf605012a5
Reviewed-on: https://chromium-review.googlesource.com/1204729Reviewed-by: Mounir Lamouri <mlamouri@chromium.org>
Commit-Queue: Becca Hughes <beccahughes@chromium.org>
Cr-Commit-Position: refs/heads/master@{#588684}

third_party/blink/renderer/core/html/media/autoplay_policy.cc

@@ -386,9 +386,6 @@ void AutoplayPolicy::EnsureAutoplayInitiatedSet() {
 
 bool AutoplayPolicy::IsGestureNeededForPlaybackIfPendingUserGestureIsLocked()
     const {
-  if (element_->GetLoadType() == WebMediaPlayer::kLoadTypeMediaStream)
-    return false;
-
   // We want to allow muted video to autoplay if:
   // - the flag is enabled;
   // - Data Saver is not enabled;