Clear out some minor TODOs.

BUG=none

Review URL: https://codereview.chromium.org/1047063002

Cr-Commit-Position: refs/heads/master@{#322959}
int CardUnmaskPromptViews::GetHeightForWidth(int width) const {
  if (!has_children())
    return 0;
  const gfx::Insets insets = GetInsets();
  return main_contents_->GetHeightForWidth(width - insets.width()) +
         insets.height();
}

int CardUnmaskPromptViews::GetHeightForWidth(int width) const {
  if (!has_children())
    return 0;
  const gfx::Insets insets = GetInsets();
  return main_contents_->GetHeightForWidth(width - insets.width()) +
         insets.height();
}
