[Sync] Fix namespaces for the sync_sessions component.

components/sync_sessions/tab_node_pool.cc

Index: components/sync_sessions/tab_node_pool.cc
diff --git a/components/sync_sessions/tab_node_pool.cc b/components/sync_sessions/tab_node_pool.cc
index 11eb38d455df714b07b8d6934d16a0c982c5998a..6ad5da7771d65405fb47bbaba0311528fb42457e 100644
--- a/components/sync_sessions/tab_node_pool.cc
+++ b/components/sync_sessions/tab_node_pool.cc
@@ -13,7 +13,7 @@
 #include "components/sync/protocol/session_specifics.pb.h"
 #include "components/sync/protocol/sync.pb.h"
 
-namespace browser_sync {
+namespace sync_sessions {
 
 const size_t TabNodePool::kFreeNodesLowWatermark = 25;
 const size_t TabNodePool::kFreeNodesHighWatermark = 100;
@@ -179,4 +179,4 @@ void TabNodePool::SetMachineTag(const std::string& machine_tag) {
   machine_tag_ = machine_tag;
 }
 
-}  // namespace browser_sync
+}  // namespace sync_sessions