arc: bluetooth: Change DCHECK to an early return

The DCHECKs used ArcBluetoothBridge::ReadGattCharacteristic() can be
triggered in some cases. Change them to real checks to avoid crashes.

Bug: chromium:1243075
Test: Build
Change-Id: I76ad299712934a03b43360f9da645456e6837582
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/3193239
Reviewed-by: Hidehiko Abe <[email protected]>
Commit-Queue: Jie Jiang <[email protected]>
Cr-Commit-Position: refs/heads/main@{#927559}

Author: Jie Jiang

chrome/browser/ash/arc/bluetooth/arc_bluetooth_bridge.cc

@@ -1705,8 +1705,21 @@ void ArcBluetoothBridge::ReadGattCharacteristic(
     ReadGattCharacteristicCallback callback) {
   BluetoothRemoteGattCharacteristic* characteristic = FindGattCharacteristic(
       std::move(remote_addr), std::move(service_id), std::move(char_id));
-  DCHECK(characteristic);
-  DCHECK(characteristic->GetPermissions() & kGattReadPermission);
+  if (!characteristic) {
+    // TODO(b/201737474): Investigate in what case this could happen.
+    LOG(ERROR) << "Requested GATT characteristic does not exist";
+    OnGattRead(std::move(callback),
+               device::BluetoothGattService::GATT_ERROR_FAILED, /*result=*/{});
+    return;
+  }
+  if (!(characteristic->GetPermissions() & kGattReadPermission)) {
+    // TODO(b/201737474): Investigate in what case this could happen.
+    LOG(ERROR) << "Requested GATT characteristic does not have read permission";
+    OnGattRead(std::move(callback),
+               device::BluetoothGattService::GATT_ERROR_NOT_PERMITTED,
+               /*result=*/{});
+    return;
+  }
 
   characteristic->ReadRemoteCharacteristic(
       base::BindOnce(&OnGattRead, std::move(callback)));