Changes ComputeTaskManager class to inherit base.Base

This is going to be needed for all migrations to conductor tasks
in order to get db access. We patch it separately to reduce
conflicts.

Partially implements bp cold-migrations-to-conductor

Change-Id: Icd686d373472498ed77f3133f655454aa035ae43

nova/conductor/manager.py

@@ -21,6 +21,7 @@ from nova import block_device
 from nova.cells import rpcapi as cells_rpcapi
 from nova.compute import api as compute_api
 from nova.compute import utils as compute_utils
+from nova.db import base
 from nova import exception
 from nova import manager
 from nova import network
@@ -545,7 +546,7 @@ class ConductorManager(manager.Manager):
         self.compute_api.reboot(context, instance, reboot_type)
 
 
-class ComputeTaskManager(object):
+class ComputeTaskManager(base.Base):
     """Namespace for compute methods.
 
     This class presents an rpc API for nova-conductor under the 'compute_task'
@@ -558,6 +559,7 @@ class ComputeTaskManager(object):
     RPC_API_VERSION = '1.2'
 
     def __init__(self):
+        super(ComputeTaskManager, self).__init__()
         self.scheduler_rpcapi = scheduler_rpcapi.SchedulerAPI()
 
     @rpc_common.client_exceptions(exception.NoValidHost,