Merge "Removed always running preDrawListener"

    private ExpandableView.OnHeightChangedListener mOnHeightChangedListener;

    private boolean mChildHierarchyDirty;

    private boolean mIsExpanded = true;

    private boolean mChildrenNeedUpdate;

    private ViewTreeObserver.OnPreDrawListener mPreDrawListener

    private boolean mChildrenUpdateRequested;

    private ViewTreeObserver.OnPreDrawListener mChildrenUpdater

            = new ViewTreeObserver.OnPreDrawListener() {

        @Override

        public boolean onPreDraw() {

            if (mChildrenNeedUpdate) {

            updateChildren();

                mChildrenNeedUpdate = false;

            }

            mChildrenUpdateRequested = false;

            getViewTreeObserver().removeOnPreDrawListener(this);

            return true;

        }

    };

        mPaddingBetweenElements = context.getResources()

                .getDimensionPixelSize(R.dimen.notification_padding);

        mStackScrollAlgorithm = new StackScrollAlgorithm(context);

        getViewTreeObserver().addOnPreDrawListener(mPreDrawListener);

    }

    @Override

    }

    private void requestChildrenUpdate() {

        mChildrenNeedUpdate = true;

        if (!mChildrenUpdateRequested) {

            getViewTreeObserver().addOnPreDrawListener(mChildrenUpdater);

            mChildrenUpdateRequested = true;

            invalidate();

        }

    }

    private boolean isCurrentlyAnimating() {

        return mStateAnimator.isRunning();