Remove TabContents from TabStripModelObserver::TabDetachedAt.

BUG=107201
TEST=no visible change


Review URL: https://chromiumcodereview.appspot.com/11293205

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@167122 0039d316-1c4b-4281-b951-d872f2087c98
  virtual void AnimationProgressed(const ui::Animation* animation) {
    TabAnimation::AnimationProgressed(animation);

    int x = animation_.CurrentValueBetween(start_bounds_.x(),
                                           target_bounds_.x());
    int width = animation_.CurrentValueBetween(start_bounds_.width(),
                                               target_bounds_.width());
    gfx::Rect tab_bounds(x, start_bounds_.y(), width,
                         start_bounds_.height());
    tabstrip_->SetTabBounds(tab_, tab_bounds);
  }

  virtual void AnimationProgressed(const ui::Animation* animation) {
    TabAnimation::AnimationProgressed(animation);

    int x = animation_.CurrentValueBetween(start_bounds_.x(),
                                           target_bounds_.x());
    int width = animation_.CurrentValueBetween(start_bounds_.width(),
                                               target_bounds_.width());
    gfx::Rect tab_bounds(x, start_bounds_.y(), width,
                         start_bounds_.height());
    tabstrip_->SetTabBounds(tab_, tab_bounds);
  }
