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 WebLocalFrameImpl::SetIsolatedWorldSecurityOrigin(
    int world_id,
    const WebSecurityOrigin& security_origin) {
  DCHECK(GetFrame());
  DOMWrapperWorld::SetIsolatedWorldSecurityOrigin(world_id,
                                                  security_origin.Get());
}

void WebLocalFrameImpl::SetIsolatedWorldSecurityOrigin(
    int world_id,
    const WebSecurityOrigin& security_origin) {
  DCHECK(GetFrame());
  DOMWrapperWorld::SetIsolatedWorldSecurityOrigin(world_id,
                                                  security_origin.Get());
}
