private void performLayout(WindowManager.LayoutParams lp, int desiredWindowWidth,
            int desiredWindowHeight) {
        mLayoutRequested = false;
        mScrollMayChange = true;
        mInLayout = true;

        final View host = mView;
        ……
        try {
            host.layout(
 
0, 0, host.getMeasuredWidth(), host.getMeasuredHeight());

            mInLayout = false;
            int numViewsRequestingLayout = mLayoutRequesters.size();
            if (numViewsRequestingLayout > 0) {
              ……
                if (validLayoutRequesters != null) {
                    
 
// Set this flag to indicate that any further requests are happening during
                   ……
                    host.layout(0, 0, host.getMeasuredWidth(), host.getMeasuredHeight());

                   ……                   
 }
                }

            }
        } finally {
            Trace.traceEnd(Trace.TRACE_TAG_VIEW);
        }
        mInLayout 
 
= false;
    }