Add WebElement::isEditable.

This will replace RenderViewImpl::IsEditableNode, and fixes
bugs where for example a <fieldset disabled> would not be
accounted for. It also adds tests for this API.

R=dglazkov@chromium.org

Review URL: https://codereview.chromium.org/1347893002

git-svn-id: svn://svn.chromium.org/blink/trunk/public@202307 bbb929c8-8fbe-4397-9dbb-9b2b20218538
1 file changed