Defer media playback in background tabs.
Videos which autoplay in the background will now have their load
deferred until the tab is visible for the first time -- this avoids
autoplay during session restore and premature playback.
Once a tab / RenderFrame has ever played media before, it's allowed
to continue to autoplay/autoload indefinitely; this is to support
playlist type applications.
TEST=manual verification that background tabs don't autoplay;
playlist type media continues to work.
Review URL: https://codereview.chromium.org/1292433002
14 files changed