Remove dead code from RenderEmbeddedObject

Since canHaveChildren() is always false in this function, everything
after the !canHaveChildren() check in layout() is a no-op.
RenderPart::layout() is also a no-op except for clearing the needsLayout
bit (which RenderEmbeddedObject does itself anyway) so remove that too.
Finally all the overrides of the RenderObjectChildList were unused, so
remove them too.

Review URL: https://codereview.chromium.org/246793006

git-svn-id: svn://svn.chromium.org/blink/trunk@172406 bbb929c8-8fbe-4397-9dbb-9b2b20218538
document.open(): gracefully handle exception thrown on window.open access.

Check if the "open" property lookup on the global object returned anything
before attempting to use it.

R=haraken@chromium.org
BUG=365659
TEST=fast/js/document-open-getter-throw-no-crash.html

Review URL: https://codereview.chromium.org/249653002

git-svn-id: svn://svn.chromium.org/blink/trunk@172407 bbb929c8-8fbe-4397-9dbb-9b2b20218538