Check that RWHI isn't deleted manually while owned by a scoped_ptr in RVHI

BUG=590284

Review URL: https://codereview.chromium.org/1747183002

Cr-Commit-Position: refs/heads/master@{#378844}
void RenderWidgetHostImpl::NotifyScreenInfoChanged() {
  color_profile_out_of_date_ = true;

  if (delegate_)
    delegate_->ScreenInfoChanged();

  WasResized();
}

void RenderWidgetHostImpl::NotifyScreenInfoChanged() {
  color_profile_out_of_date_ = true;

  if (delegate_)
    delegate_->ScreenInfoChanged();

  WasResized();
}
