Simplified emit_post_migrate from flush command

Follow-up of f4f24d30e0.

django/core/management/commands/flush.py

@@ -7,7 +7,7 @@ from django.apps import apps
 from django.core.management.base import BaseCommand, CommandError
 from django.core.management.color import no_style
 from django.core.management.sql import emit_post_migrate_signal, sql_flush
-from django.db import DEFAULT_DB_ALIAS, connections, router, transaction
+from django.db import DEFAULT_DB_ALIAS, connections, transaction
 from django.utils import six
 from django.utils.six.moves import input
 
@@ -76,15 +76,8 @@ Are you sure you want to do this?
                 six.reraise(CommandError, CommandError(new_msg), sys.exc_info()[2])
 
             if not inhibit_post_migrate:
-                self.emit_post_migrate(verbosity, interactive, database)
+                # Emit the post migrate signal. This allows individual applications to
+                # respond as if the database had been migrated from scratch.
+                emit_post_migrate_signal(verbosity, interactive, database)
         else:
             self.stdout.write("Flush cancelled.\n")
-
-    @staticmethod
-    def emit_post_migrate(verbosity, interactive, database):
-        # Emit the post migrate signal. This allows individual applications to
-        # respond as if the database had been migrated from scratch.
-        all_models = []
-        for app_config in apps.get_app_configs():
-            all_models.extend(router.get_migratable_models(app_config, database, include_auto_created=True))
-        emit_post_migrate_signal(verbosity, interactive, database)

django/test/testcases.py

@@ -23,7 +23,7 @@ from django.core.exceptions import ImproperlyConfigured, ValidationError
 from django.core.handlers.wsgi import WSGIHandler, get_path_info
 from django.core.management import call_command
 from django.core.management.color import no_style
-from django.core.management.commands import flush
+from django.core.management.sql import emit_post_migrate_signal
 from django.core.servers.basehttp import WSGIRequestHandler, WSGIServer
 from django.core.urlresolvers import clear_url_caches, set_urlconf
 from django.db import DEFAULT_DB_ALIAS, connection, connections, transaction
@@ -777,7 +777,7 @@ class TransactionTestCase(SimpleTestCase):
                                  value=self.available_apps,
                                  enter=True)
             for db_name in self._databases_names(include_mirrors=False):
-                flush.Command.emit_post_migrate(verbosity=0, interactive=False, database=db_name)
+                emit_post_migrate_signal(verbosity=0, interactive=False, db=db_name)
         try:
             self._fixture_setup()
         except Exception: