This introduces a new kind of ContentNode similar to Style but which
instead of changing the styles that apply to the node, provides new
settings to apply to the "parentData" structure.
R=eseidel@chromium.org
Review URL: https://codereview.chromium.org/1122413006
We dropped Anchor support, and the markup changed a bit (mostly it got debug='' attributes to help debug output).
TBR=eseidel
Review URL: https://codereview.chromium.org/1129883004