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

content/renderer/pepper/pepper_plugin_registry.cc

 // Copyright (c) 2012 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 "content/renderer/pepper/pepper_plugin_registry.h"
 
 #include <stddef.h>
 
 #include "base/logging.h"
 #include "content/common/pepper_plugin_list.h"
@@ skipping 21 matching lines @@
     if (info.path == plugin_list_[i].path)
       return &plugin_list_[i];
   }
   // We did not find the plugin in our list. But wait! the plugin can also
   // be a latecomer, as it happens with pepper flash. This information
   // is actually in |info| and we can use it to construct it and add it to
   // the list. This same deal needs to be done in the browser side in
   // PluginService.
   PepperPluginInfo plugin;
   if (!MakePepperPluginInfo(info, &plugin))
-    return NULL;
+    return nullptr;
 
   plugin_list_.push_back(plugin);
-  return &plugin_list_[plugin_list_.size() - 1];
+  return &plugin_list_.back();
 }
 
 PluginModule* PepperPluginRegistry::GetLiveModule(const base::FilePath& path) {
   NonOwningModuleMap::iterator module_iter = live_modules_.find(path);
   if (module_iter == live_modules_.end())
     return NULL;
 
   // Check the instances for the module to see if they've all been Delete()d.
   // We don't want to return a PluginModule in that case, since the plugin may
   // have exited already.
@@ skipping 77 matching lines @@
       if (!module->InitAsLibrary(current.path)) {
         DVLOG(1) << "Failed to load pepper module: " << current.path.value();
         continue;
       }
     }
     preloaded_modules_[current.path] = module;
   }
 }
 
 }  // namespace content