Code: void StopCastCallback(
    CastConfigDelegate* cast_config,
    const CastConfigDelegate::ReceiversAndActivites& receivers_activities) {
  for (auto& item : receivers_activities) {
    CastConfigDelegate::Activity activity = item.second.activity;
    if (activity.allow_stop && activity.id.empty() == false)
      cast_config->StopCasting(activity.id);
  }
}

Vulnerability Type: XSS 
CWE ID: CWE-79
Summary: Cross-site scripting (XSS) vulnerability in the DocumentLoader::maybeCreateArchive function in core/loader/DocumentLoader.cpp in Blink, as used in Google Chrome before 35.0.1916.114, allows remote attackers to inject arbitrary web script or HTML via crafted MHTML content, aka *Universal XSS (UXSS).*
Commit Message: Allow the cast tray to function as expected when the installed extension is missing API methods.

BUG=489445

Review URL: https://codereview.chromium.org/1145833003

Cr-Commit-Position: refs/heads/master@{#330663}