[Sync] Fix namespaces for the browser_sync component.

chrome/browser/sync/sync_startup_tracker_unittest.cc

Index: chrome/browser/sync/sync_startup_tracker_unittest.cc
diff --git a/chrome/browser/sync/sync_startup_tracker_unittest.cc b/chrome/browser/sync/sync_startup_tracker_unittest.cc
index 195c6a67261a5396325365bceba08cd7d1088b78..9913562de371552170780a7bf13b6ff5e97009ec 100644
--- a/chrome/browser/sync/sync_startup_tracker_unittest.cc
+++ b/chrome/browser/sync/sync_startup_tracker_unittest.cc
@@ -34,7 +34,7 @@ class SyncStartupTrackerTest : public testing::Test {
   }
   void SetUp() override {
     profile_.reset(new TestingProfile());
-    mock_pss_ = static_cast<ProfileSyncServiceMock*>(
+    mock_pss_ = static_cast<browser_sync::ProfileSyncServiceMock*>(
         ProfileSyncServiceFactory::GetInstance()->SetTestingFactoryAndUse(
             profile_.get(), BuildMockProfileSyncService));
 
@@ -64,7 +64,7 @@ class SyncStartupTrackerTest : public testing::Test {
   content::TestBrowserThreadBundle thread_bundle_;
   GoogleServiceAuthError no_error_;
   std::unique_ptr<TestingProfile> profile_;
-  ProfileSyncServiceMock* mock_pss_;
+  browser_sync::ProfileSyncServiceMock* mock_pss_;
   MockObserver observer_;
 };