Use std::tie() for operator< in content/

content/browser/host_zoom_map_impl.h

 // 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.
 
 #ifndef CONTENT_BROWSER_HOST_ZOOM_MAP_IMPL_H_
 #define CONTENT_BROWSER_HOST_ZOOM_MAP_IMPL_H_
 
 #include <map>
 #include <string>
+#include <tuple>
 #include <vector>
 
 #include "base/compiler_specific.h"
 #include "base/sequenced_task_runner_helpers.h"
 #include "base/synchronization/lock.h"
 #include "content/public/browser/host_zoom_map.h"
 #include "content/public/browser/notification_observer.h"
 #include "content/public/browser/notification_registrar.h"
 
 namespace content {
@@ skipping 85 matching lines @@
   typedef std::map<std::string, double> HostZoomLevels;
   typedef std::map<std::string, HostZoomLevels> SchemeHostZoomLevels;
 
   struct RenderViewKey {
     int render_process_id;
     int render_view_id;
     RenderViewKey(int render_process_id, int render_view_id)
         : render_process_id(render_process_id),
           render_view_id(render_view_id) {}
     bool operator<(const RenderViewKey& other) const {
-      return render_process_id < other.render_process_id ||
-             ((render_process_id == other.render_process_id) &&
-              (render_view_id < other.render_view_id));
+      return std::tie(render_process_id, render_view_id) <
+             std::tie(other.render_process_id, other.render_view_id);
     }
   };
 
   typedef std::map<RenderViewKey, double> TemporaryZoomLevels;
   typedef std::map<RenderViewKey, bool> ViewPageScaleFactorsAreOne;
 
   double GetZoomLevelForHost(const std::string& host) const;
 
   // Non-locked versions for internal use. These should only be called within
   // a scope where a lock has been acquired.
@@ skipping 30 matching lines @@
   mutable base::Lock lock_;
 
   NotificationRegistrar registrar_;
 
   DISALLOW_COPY_AND_ASSIGN(HostZoomMapImpl);
 };
 
 }  // namespace content
 
 #endif  // CONTENT_BROWSER_HOST_ZOOM_MAP_IMPL_H_