Inherit CSP when we inherit the security origin

This prevents attacks that use main window navigation to get out of the
existing csp constraints such as the related bug

Bug: 747847
Change-Id: I1e57b50da17f65d38088205b0a3c7c49ef2ae4d8
Reviewed-on: https://chromium-review.googlesource.com/592027
Reviewed-by: Mike West <mkwst@chromium.org>
Commit-Queue: Andy Paicu <andypaicu@chromium.org>
Cr-Commit-Position: refs/heads/master@{#492333}
Color Document::ThemeColor() const {
  auto root_element = documentElement();
  if (!root_element)
    return Color();
  for (HTMLMetaElement& meta_element :
       Traversal<HTMLMetaElement>::DescendantsOf(*root_element)) {
    Color color = Color::kTransparent;
    if (DeprecatedEqualIgnoringCase(meta_element.GetName(), "theme-color") &&
        CSSParser::ParseColor(
            color, meta_element.Content().GetString().StripWhiteSpace(), true))
      return color;
  }
  return Color();
}

Color Document::ThemeColor() const {
  auto root_element = documentElement();
  if (!root_element)
    return Color();
  for (HTMLMetaElement& meta_element :
       Traversal<HTMLMetaElement>::DescendantsOf(*root_element)) {
    Color color = Color::kTransparent;
    if (DeprecatedEqualIgnoringCase(meta_element.GetName(), "theme-color") &&
        CSSParser::ParseColor(
            color, meta_element.Content().GetString().StripWhiteSpace(), true))
      return color;
  }
  return Color();
}
