Sync: fix crash in DeviceInfoDataTypeController::Subscription destructor.

components/sync_driver/device_info_data_type_controller_unittest.cc

Index: components/sync_driver/device_info_data_type_controller_unittest.cc
diff --git a/components/sync_driver/device_info_data_type_controller_unittest.cc b/components/sync_driver/device_info_data_type_controller_unittest.cc
index 137ed253a10eb754173c8c76d69e912f0bdcf4fd..c6535cbb5ef28ca2f160c3a69f07ad9312e613ea 100644
--- a/components/sync_driver/device_info_data_type_controller_unittest.cc
+++ b/components/sync_driver/device_info_data_type_controller_unittest.cc
@@ -127,6 +127,19 @@ TEST_F(DeviceInfoDataTypeControllerTest, StartModelsDelayedByLocalDevice) {
   EXPECT_TRUE(LoadResult());
 }
 
+// Tests that DeviceInfoDataTypeControllerTest handles the situation
+// when everything stops before the start gets a chance to finish.
+TEST_F(DeviceInfoDataTypeControllerTest, DestructionWithDelayedStart) {
+  local_device_->SetInitialized(false);
+  Start();
+
+  controller_->Stop();
+  // Destroy |local_device_| and |controller_| out of order
+  // to verify that the controller doesn't crash in the destructor.
+  local_device_.reset();
+  controller_ = NULL;
+}
+
 }  // namespace
 
 }  // namespace sync_driver