Rename shell namespace to service_manager

ash/mus/accelerators/accelerator_registrar_unittest.cc

Index: ash/mus/accelerators/accelerator_registrar_unittest.cc
diff --git a/ash/mus/accelerators/accelerator_registrar_unittest.cc b/ash/mus/accelerators/accelerator_registrar_unittest.cc
index 44202d0f17fa926d6601bf80f6022045ea678b19..2f8d74e4a0392cdba5ca42ff9e0e627edadc1b10 100644
--- a/ash/mus/accelerators/accelerator_registrar_unittest.cc
+++ b/ash/mus/accelerators/accelerator_registrar_unittest.cc
@@ -67,9 +67,10 @@ class TestAcceleratorHandler : public AcceleratorHandler {
   DISALLOW_COPY_AND_ASSIGN(TestAcceleratorHandler);
 };
 
-class AcceleratorRegistrarTest : public shell::test::ServiceTest {
+class AcceleratorRegistrarTest : public service_manager::test::ServiceTest {
  public:
-  AcceleratorRegistrarTest() : shell::test::ServiceTest("exe:mash_unittests") {}
+  AcceleratorRegistrarTest()
+      : service_manager::test::ServiceTest("exe:mash_unittests") {}
   ~AcceleratorRegistrarTest() override {}
 
  protected: