[Sync] Fix namespaces for the sync_sessions component.

components/sync_sessions/BUILD.gn

Index: components/sync_sessions/BUILD.gn
diff --git a/components/sync_sessions/BUILD.gn b/components/sync_sessions/BUILD.gn
index 1df87ff54a5a351d439a97e6827d2f5d935953f1..037dfb6bb866ef2ef576386b58641bcae9a73587 100644
--- a/components/sync_sessions/BUILD.gn
+++ b/components/sync_sessions/BUILD.gn
@@ -49,14 +49,17 @@ static_library("sync_sessions") {
     "tab_node_pool.h",
   ]
 
+  public_deps = [
+    "//components/sessions",
+    "//components/sync",
+  ]
+
   deps = [
     "//base",
     "//components/bookmarks/browser",
     "//components/favicon/core",
     "//components/history/core/browser",
     "//components/prefs",
-    "//components/sessions",
-    "//components/sync",
     "//components/variations",
     "//ui/base:base",
     "//ui/gfx",
@@ -69,11 +72,15 @@ static_library("test_support") {
   sources = [
     "fake_sync_sessions_client.cc",
     "fake_sync_sessions_client.h",
+    "session_sync_test_helper.cc",
+    "session_sync_test_helper.h",
   ]
 
   public_deps = [
     ":sync_sessions",
     "//base",
+    "//components/sync",
+    "//testing/gtest",
     "//url",
   ]