Use ElementTraversal API in ContainerNode::checkForChildrenAdjacentRuleChanges()

Use ElementTraversal API in ContainerNode::checkForChildrenAdjacentRuleChanges()
as we are only interested in child Elements.

R=esprehn@chromium.org

Review URL: https://codereview.chromium.org/316173007

git-svn-id: svn://svn.chromium.org/blink/trunk@175722 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Eliminate MediaPlayer & MediaPlayerClient abstractions(readystate)

BUG=350571

Review URL: https://codereview.chromium.org/318923004

git-svn-id: svn://svn.chromium.org/blink/trunk@175723 bbb929c8-8fbe-4397-9dbb-9b2b20218538