[Sync] Initial USS service implementation for DeviceInfo.

components/sync_driver/device_info_service_unittest.cc

+// Copyright 2015 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "components/sync_driver/device_info_service.h"
+
+#include <string>
+
+#include "components/sync_driver/local_device_info_provider_mock.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace sync_driver {
+
+namespace {
+
+class DeviceInfoServiceTest : public testing::Test,
+                              public DeviceInfoTracker::Observer {
+ protected:
+  DeviceInfoServiceTest() : num_device_info_changed_callbacks_(0) {}
+
+  void InitFully() {
+    local_device_.reset(new LocalDeviceInfoProviderMock(
+        "guid_1", "client_1", "Chromium 10k", "Chrome 10k",
+        sync_pb::SyncEnums_DeviceType_TYPE_LINUX, "device_id"));
+    service_.reset(new DeviceInfoService(local_device_.get()));
+    service_->AddObserver(this);
+  }
+
+  void InitPartially() {
+    local_device_.reset(new LocalDeviceInfoProviderMock());
+    service_.reset(new DeviceInfoService(local_device_.get()));
+    service_->AddObserver(this);
+  }
+
+  ~DeviceInfoServiceTest() override { service_->RemoveObserver(this); }
+
+  void OnDeviceInfoChange() override { num_device_info_changed_callbacks_++; }
+
+ protected:
+  int num_device_info_changed_callbacks_;
+  scoped_ptr<LocalDeviceInfoProviderMock> local_device_;
+  scoped_ptr<DeviceInfoService> service_;
+};
+
+TEST_F(DeviceInfoServiceTest, StartSyncEmptyInitialData) {
+  InitFully();
+  EXPECT_FALSE(service_->IsSyncing());
+}
+
+TEST_F(DeviceInfoServiceTest, DelayedProviderInitialization) {
+  InitPartially();
+  local_device_->Initialize(make_scoped_ptr(
+      new DeviceInfo("guid_1", "client_1", "Chromium 10k", "Chrome 10k",
+                     sync_pb::SyncEnums_DeviceType_TYPE_LINUX, "device_id")));
+
+  EXPECT_FALSE(service_->IsSyncing());
+}
+
+}  // namespace
+
+}  // namespace sync_driver