Merge "Fix potential NPE if there is no child in HorizontalScrollView"

    @Override

    protected void onLayout(boolean changed, int l, int t, int r, int b) {

        // There is only one child

        final View child = getChildAt(0);

        final int childWidth = child.getMeasuredWidth();

        final LayoutParams childParams = (LayoutParams) child.getLayoutParams();

        int childWidth = 0;

        int childMargins = 0;

        if (getChildCount() > 0) {

            childWidth = getChildAt(0).getMeasuredWidth();

            LayoutParams childParams = (LayoutParams) getChildAt(0).getLayoutParams();

            childMargins = childParams.leftMargin + childParams.rightMargin;

        }

        final int available = r - l - getPaddingLeftWithForeground() -

                getPaddingRightWithForeground() - childParams.leftMargin - childParams.rightMargin;

                getPaddingRightWithForeground() - childMargins;

        final boolean forceLeftGravity = (childWidth > available);

        layoutChildren(l, t, r, b, forceLeftGravity);

        mIsLayoutDirty = false;

        // Give a child focus if it needs it

        if (mChildToScrollTo != null && isViewDescendantOf(mChildToScrollTo, this)) {