[Sync] Fix namespaces for the sync_sessions component.

components/sync_sessions/tab_node_pool_unittest.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 <stddef.h>
 
 #include <vector>
 
 #include "components/sync/api/sync_change.h"
 #include "components/sync/protocol/session_specifics.pb.h"
 #include "components/sync/protocol/sync.pb.h"
 #include "testing/gtest/include/gtest/gtest.h"
 
-namespace browser_sync {
+namespace sync_sessions {
 
 class SyncTabNodePoolTest : public testing::Test {
  protected:
   SyncTabNodePoolTest() { pool_.SetMachineTag("tag"); }
 
   int GetMaxUsedTabNodeId() const { return pool_.max_used_tab_node_id_; }
 
   void AddFreeTabNodes(size_t size, const int node_ids[]);
 
   TabNodePool pool_;
@@ skipping 227 matching lines @@
   // Freeing the last sync node should drop the free nodes to
   // kFreeNodesLowWatermark.
   pool_.FreeTabNode(last_sync_id, &changes);
   EXPECT_FALSE(pool_.Empty());
   EXPECT_TRUE(pool_.Full());
   EXPECT_EQ(TabNodePool::kFreeNodesLowWatermark, pool_.Capacity());
 }
 
 }  // namespace
 
-}  // namespace browser_sync
+}  // namespace sync_sessions