Merge "Ensure waitForIdle() waits until pending messages are handled." into...

            mContext.enforceCallingOrSelfPermission(android.Manifest.permission.DUMP,

                    "Caller is not allowed to call this; caller=" + Binder.getCallingUid());

            // We post messages back and forth between mHandler thread and mBackgroundHandler

            // thread while committing a blob. We need to replicate the same pattern here to

            // ensure pending messages have been handled.

            mHandler.post(() -> {

                mBackgroundHandler.post(() -> {

                    mHandler.post(PooledLambda.obtainRunnable(remoteCallback::sendResult, null)

                            .recycleOnUse());

                });

            });

        }

        @Override