[sync] WebContentsObserver based sessions notifications

components/sync_sessions/tab_node_pool.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "components/sync_sessions/tab_node_pool.h"
 
 #include <algorithm>
 
 #include "base/logging.h"
 #include "components/sync/base/model_type.h"
 #include "components/sync/protocol/session_specifics.pb.h"
 #include "components/sync/protocol/sync.pb.h"
+#include "components/sync_sessions/synced_tab_delegate.h"
 
 namespace sync_sessions {
 
 const size_t TabNodePool::kFreeNodesLowWatermark = 25;
 const size_t TabNodePool::kFreeNodesHighWatermark = 100;
 
 TabNodePool::TabNodePool() : max_used_tab_node_id_(kInvalidTabNodeID) {}
 
 // static
 // We start vending tab node IDs at 0.
@@ skipping 127 matching lines @@
 
 bool TabNodePool::Empty() const {
   return free_nodes_pool_.empty();
 }
 
 bool TabNodePool::Full() {
   return nodeid_tabid_map_.empty();
 }
 
 }  // namespace sync_sessions