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}
void Document::ViewportDefiningElementDidChange() {
  HTMLBodyElement* body = FirstBodyElement();
  if (!body)
    return;
  LayoutObject* layout_object = body->GetLayoutObject();
  if (layout_object && layout_object->IsLayoutBlock()) {
    layout_object->SetStyle(ComputedStyle::Clone(*layout_object->Style()));
  }
}

void Document::ViewportDefiningElementDidChange() {
  HTMLBodyElement* body = FirstBodyElement();
  if (!body)
    return;
  LayoutObject* layout_object = body->GetLayoutObject();
  if (layout_object && layout_object->IsLayoutBlock()) {
    layout_object->SetStyle(ComputedStyle::Clone(*layout_object->Style()));
  }
}
