wstring: remove wstring version of SplitString

Retry of r84336.

BUG=23581

Review URL: http://codereview.chromium.org/6930047

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@84355 0039d316-1c4b-4281-b951-d872f2087c98
void Label::OnBoundsChanged(const gfx::Rect& previous_bounds) {
  text_size_valid_ &= !is_multi_line_;
}

void Label::OnBoundsChanged(const gfx::Rect& previous_bounds) {
  text_size_valid_ &= !is_multi_line_;
}
