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}
Range* Document::caretRangeFromPoint(int x, int y) {
  if (GetLayoutViewItem().IsNull())
    return nullptr;

  HitTestResult result = HitTestInDocument(this, x, y);
  PositionWithAffinity position_with_affinity = result.GetPosition();
  if (position_with_affinity.IsNull())
    return nullptr;

  Position range_compliant_position =
      position_with_affinity.GetPosition().ParentAnchoredEquivalent();
  return Range::CreateAdjustedToTreeScope(*this, range_compliant_position);
}

Range* Document::caretRangeFromPoint(int x, int y) {
  if (GetLayoutViewItem().IsNull())
    return nullptr;

  HitTestResult result = HitTestInDocument(this, x, y);
  PositionWithAffinity position_with_affinity = result.GetPosition();
  if (position_with_affinity.IsNull())
    return nullptr;

  Position range_compliant_position =
      position_with_affinity.GetPosition().ParentAnchoredEquivalent();
  return Range::CreateAdjustedToTreeScope(*this, range_compliant_position);
}
