Remove thread delegation when checking grants.

        @Override

        public int checkContentProviderUriPermission(Uri uri, int userId,

                int callingUid, int modeFlags) {

            // We can find ourselves needing to check Uri permissions while

            // already holding the WM lock, which means reaching back here for

            // the AM lock would cause an inversion. The WM team has requested

            // that we use the strategy below instead of shifting where Uri

            // grants are calculated.

            // Since we could also arrive here while holding the AM lock, we

            // can't always delegate the call through the handler, and we need

            // to delicately dance between the deadlocks.

            if (Thread.currentThread().holdsLock(ActivityManagerService.this)) {

            return ActivityManagerService.this.checkContentProviderUriPermission(uri,

                    userId, callingUid, modeFlags);

            } else {

                final CompletableFuture<Integer> res = new CompletableFuture<>();

                mHandler.post(() -> {

                    res.complete(ActivityManagerService.this.checkContentProviderUriPermission(uri,

                            userId, callingUid, modeFlags));

                });

                try {

                    return res.get();

                } catch (InterruptedException | ExecutionException e) {

                    throw new RuntimeException(e);

                }

            }

        }

        @Override