[Sync] Fix test support targets + duplicate namespaces.

components/browser_sync/BUILD.gn

Index: components/browser_sync/BUILD.gn
diff --git a/components/browser_sync/BUILD.gn b/components/browser_sync/BUILD.gn
index 7a42726915ef84f8c2174cb29a15995c2a1f058d..d7a68ac4aae35f4695b93a442f6d848c64d312c2 100644
--- a/components/browser_sync/BUILD.gn
+++ b/components/browser_sync/BUILD.gn
@@ -78,8 +78,9 @@ source_set("unit_tests") {
     "//components/signin/core/common:common",
     "//components/strings",
     "//components/sync",
-    "//components/sync:test_support_sync_core_impl",
-    "//components/sync:test_support_sync_driver",
+    "//components/sync:test_support_driver",
+    "//components/sync:test_support_engine",
+    "//components/sync:test_support_model",
     "//components/sync_bookmarks:sync_bookmarks",
     "//components/sync_sessions",
     "//components/sync_sessions:test_support",
@@ -123,9 +124,8 @@ static_library("test_support") {
     "//components/signin/core/browser:browser",
     "//components/signin/core/browser:test_support",
     "//components/sync",
-    "//components/sync:test_support_sync_core",
-    "//components/sync:test_support_sync_core_impl",
-    "//components/sync:test_support_sync_driver",
+    "//components/sync:test_support_driver",
+    "//components/sync:test_support_engine",
     "//components/sync_sessions:test_support",
     "//components/syncable_prefs:test_support",
     "//google_apis",