Revert of [sync] Add Sessions integration tests

components/sync/test/fake_server/sessions_hierarchy.cc

Index: components/sync/test/fake_server/sessions_hierarchy.cc
diff --git a/components/sync/test/fake_server/sessions_hierarchy.cc b/components/sync/test/fake_server/sessions_hierarchy.cc
index 204c8cd694cb640a8be403d4318b6e81a2435525..8cdde963ba802551540c0f4bc7de620695675e1e 100644
--- a/components/sync/test/fake_server/sessions_hierarchy.cc
+++ b/components/sync/test/fake_server/sessions_hierarchy.cc
@@ -10,16 +10,12 @@
 
 SessionsHierarchy::SessionsHierarchy() {}
 
-SessionsHierarchy::SessionsHierarchy(const SessionsHierarchy& other) = default;
-
-SessionsHierarchy::SessionsHierarchy(
-    std::initializer_list<std::multiset<std::string>> windows)
-    : windows_(windows) {}
-
 SessionsHierarchy::~SessionsHierarchy() {}
 
 void SessionsHierarchy::AddWindow(const std::string& tab) {
-  windows_.insert({tab});
+  SessionsHierarchy::Window window;
+  window.insert(tab);
+  windows_.insert(window);
 }
 
 void SessionsHierarchy::AddWindow(const std::multiset<std::string>& tabs) {