Code: void HTMLMediaElement::NoneSupported(const String& message) {
  BLINK_MEDIA_LOG << "NoneSupported(" << (void*)this << ", message='" << message
                  << "')";
 
   StopPeriodicTimers();
   load_state_ = kWaitingForSource;
   current_source_node_ = nullptr;
 
 
  error_ = MediaError::Create(MediaError::kMediaErrSrcNotSupported, message);

  ForgetResourceSpecificTracks();

  SetNetworkState(kNetworkNoSource);

  UpdateDisplayState();

  ScheduleEvent(EventTypeNames::error);

  ScheduleRejectPlayPromises(kNotSupportedError);

  CloseMediaSource();

  SetShouldDelayLoadEvent(false);

  if (GetLayoutObject())
    GetLayoutObject()->UpdateFromElement();
}

Vulnerability Type: +Info 
CWE ID: CWE-200
Summary: Information leak in media engine in Google Chrome prior to 68.0.3440.75 allowed a remote attacker to leak cross-origin data via a crafted HTML page.
Commit Message: defeat cors attacks on audio/video tags

Neutralize error messages and fire no progress events
until media metadata has been loaded for media loaded
from cross-origin locations.

Bug: 828265, 826187
Change-Id: Iaf15ef38676403687d6a913cbdc84f2d70a6f5c6
Reviewed-on: https://chromium-review.googlesource.com/1015794
Reviewed-by: Mounir Lamouri <mlamouri@chromium.org>
Reviewed-by: Dale Curtis <dalecurtis@chromium.org>
Commit-Queue: Fredrik Hubinette <hubbe@chromium.org>
Cr-Commit-Position: refs/heads/master@{#557312}