[NOT FOR REVIEW] Copy of Max's CL with conflicts fixed

components/sync_driver/BUILD.gn

Index: components/sync_driver/BUILD.gn
diff --git a/components/sync_driver/BUILD.gn b/components/sync_driver/BUILD.gn
index ebd1a72d3cd598a8b1f2a6042b78a82f746d1257..da46e62679a4d6964c051b27e09401c865218aa4 100644
--- a/components/sync_driver/BUILD.gn
+++ b/components/sync_driver/BUILD.gn
@@ -49,6 +49,12 @@ source_set("sync_driver") {
     "glue/browser_thread_model_worker.h",
     "glue/chrome_report_unrecoverable_error.cc",
     "glue/chrome_report_unrecoverable_error.h",
+    "glue/sync_backend_host.cc",
+    "glue/sync_backend_host.h",
+    "glue/sync_backend_host_core.cc",
+    "glue/sync_backend_host_core.h",
+    "glue/sync_backend_host_impl.cc",
+    "glue/sync_backend_host_impl.h",
     "glue/sync_backend_registrar.cc",
     "glue/sync_backend_registrar.h",
     "glue/synced_session.cc",
@@ -126,6 +132,7 @@ source_set("sync_driver") {
     "//base",
     "//base:prefs",
     "//base/third_party/dynamic_annotations",
+    "//components/data_use_measurement/core",
     "//components/invalidation/public",
     "//components/os_crypt",
     "//components/pref_registry",
@@ -172,6 +179,8 @@ source_set("test_support") {
     "fake_sync_service.h",
     "frontend_data_type_controller_mock.cc",
     "frontend_data_type_controller_mock.h",
+    "glue/sync_backend_host_mock.cc",
+    "glue/sync_backend_host_mock.h",
     "local_device_info_provider_mock.cc",
     "local_device_info_provider_mock.h",
     "model_associator_mock.cc",