Use container::back() and container::pop_back().

cc/surfaces/surface_manager.h

 // 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.
 
 #ifndef CC_SURFACES_SURFACE_MANAGER_H_
 #define CC_SURFACES_SURFACE_MANAGER_H_
 
 #include <stdint.h>
 
 #include <list>
@@ skipping 111 matching lines @@
   // this set, any remaining sequences with that namespace are considered
   // satisfied.
   std::unordered_set<uint32_t> valid_surface_id_namespaces_;
 
   // Begin frame source routing. Both BeginFrameSource and SurfaceFactoryClient
   // pointers guaranteed alive by callers until unregistered.
   struct ClientSourceMapping {
     ClientSourceMapping();
     ClientSourceMapping(const ClientSourceMapping& other);
     ~ClientSourceMapping();
-    bool is_empty() const { return !client && !children.size(); }
+    bool is_empty() const { return !client && children.empty(); }
     // The client that's responsible for creating this namespace.  Never null.
     SurfaceFactoryClient* client;
     // The currently assigned begin frame source for this client.
     BeginFrameSource* source;
     // This represents a dag of parent -> children mapping.
     std::vector<uint32_t> children;
   };
   std::unordered_map<uint32_t, ClientSourceMapping> namespace_client_map_;
   // Set of which sources are registered to which namespace.  Any child
   // that is implicitly using this namespace must be reachable by the
   // parent in the dag.
   std::unordered_map<BeginFrameSource*, uint32_t> registered_sources_;
 
   DISALLOW_COPY_AND_ASSIGN(SurfaceManager);
 };
 
 }  // namespace cc
 
 #endif  // CC_SURFACES_SURFACE_MANAGER_H_