RenderSVGResource shouldn't trigger relayout during render tree teardown

MarkForLayoutOrParentResourceInvalidation can be called in SVG during
document teardown. This change skips that if the document is being
destroyed.

This is a merge of http://trac.webkit.org/changeset/155055 by
Andreas Kling <akling@apple.com>

BUG=285368

Review URL: https://chromiumcodereview.appspot.com/23531032

git-svn-id: svn://svn.chromium.org/blink/trunk@157428 bbb929c8-8fbe-4397-9dbb-9b2b20218538
Add toHTMLDialogElement(), and use it.

We'd like to avoid bare static_cast<>.

BUG=none
TEST=none; no behavior changes.

Review URL: https://chromiumcodereview.appspot.com/23828005

git-svn-id: svn://svn.chromium.org/blink/trunk@157429 bbb929c8-8fbe-4397-9dbb-9b2b20218538
CSS Animations: add interpolation test for webkit-text-stroke-color

Review URL: https://chromiumcodereview.appspot.com/24021003

git-svn-id: svn://svn.chromium.org/blink/trunk@157430 bbb929c8-8fbe-4397-9dbb-9b2b20218538