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
void BrowserLauncherItemController::ActiveTabChanged(
    TabContents* old_contents,
    TabContents* new_contents,
    int index,
    bool user_gesture) {
  if (old_contents)
    UpdateAppState(old_contents->web_contents());
  UpdateAppState(new_contents->web_contents());
  UpdateLauncher(new_contents);
}

void BrowserLauncherItemController::ActiveTabChanged(
    TabContents* old_contents,
    TabContents* new_contents,
    int index,
    bool user_gesture) {
  if (old_contents)
    UpdateAppState(old_contents->web_contents());
  UpdateAppState(new_contents->web_contents());
  UpdateLauncher(new_contents);
}
