// Android 12
private void releaseSurfaces(Transaction transaction) {
    if (mSurfaceControl != null) {
        transaction.remove(mSurfaceControl);
        mSurfaceControl = null;
    }
    if (mBackgroundControl != null) {
        transaction.remove(mBackgroundControl);
        mBackgroundControl = null;
    }
    if (mBlastSurfaceControl != null) {
        transaction.remove(mBlastSurfaceControl);
        mBlastSurfaceControl = null;
    }
}

分别对 mSurfaceControl、mBackgroundControl 和 mBlastSurfaceControl 调用 Transaction.remove() 递减 SurfaceControl native 强引用计数。

// Android 11
private void releaseSurfaces() {
    mSurfaceAlpha = 1f;

    synchronized (mSurfaceControlLock) {
        mSurface.release();

        if (mRtHandlingPositionUpdates) {
            mRtReleaseSurfaces = true;
            return;
        }

        if (mSurfaceControl != null) {
            mTmpTransaction.remove(mSurfaceControl);
            mSurfaceControl = null;
        }
        if (mBackgroundControl != null) {
            mTmpTransaction.remove(mBackgroundControl);
            mBackgroundControl = null;
        }
        mTmpTransaction.apply();
    }
}

调用 Surface.release() 释放 mSurface，调用 Transaction.remove() 释放 mSurfaceControl 和 mBackgroundControl。