public void onAttach() {
    mEventTracker.recordEvent(Event.ON_HOLDER_ATTACH);
    mIsHolderAttached = true;
    attachOrDetachController();
  }
Gets the controller ready to display the image.

<p>The containing view must call this method from both {@link View#onFinishTemporaryDetach()}
and {@link View#onAttachedToWindow()}.
drawee/src/main/java/com/facebook/drawee/view/DraweeHolder.java