Allow selection to skip over contenteditable

BUG=264539

Review URL: https://chromiumcodereview.appspot.com/20572005

git-svn-id: svn://svn.chromium.org/blink/trunk@157492 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Fix RELEASE_ASSERT in RenderBlock::layoutPositionedObjects.

RenderVideo::updatePlayer calls setNeedsLayout if the intrinsic size changed.
This was hitting the SubtreeLayoutScope assert that the object is layouted
when the scope is destroyed. Instead, updatePlayer should be called *before*
we do the layout. In addition to fixing the assert, it just makes more sense
to do it so that layout can use the updated information.

BUG=280730

Review URL: https://chromiumcodereview.appspot.com/23455041

git-svn-id: svn://svn.chromium.org/blink/trunk@157493 bbb929c8-8fbe-4397-9dbb-9b2b20218538