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

ui/gfx/geometry/point.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 UI_GFX_GEOMETRY_POINT_H_
 #define UI_GFX_GEOMETRY_POINT_H_
 
 #include <iosfwd>
 #include <string>
+#include <tuple>
 
 #include "ui/gfx/geometry/vector2d.h"
 #include "ui/gfx/gfx_export.h"
 
 #if defined(OS_WIN)
 typedef unsigned long DWORD;
 typedef struct tagPOINT POINT;
 #elif defined(OS_MACOSX)
 typedef struct CGPoint CGPoint;
 #endif
@@ skipping 56 matching lines @@
 
   Vector2d OffsetFromOrigin() const { return Vector2d(x_, y_); }
 
   // A point is less than another point if its y-value is closer
   // to the origin. If the y-values are the same, then point with
   // the x-value closer to the origin is considered less than the
   // other.
   // This comparison is required to use Point in sets, or sorted
   // vectors.
   bool operator<(const Point& rhs) const {
-    return (y_ == rhs.y_) ? (x_ < rhs.x_) : (y_ < rhs.y_);
+    return std::tie(y_, x_) < std::tie(rhs.y_, rhs.x_);
   }
 
   // Returns a string representation of point.
   std::string ToString() const;
 
  private:
   int x_;
   int y_;
 };
 
@@ skipping 40 matching lines @@
                                      float y_scale);
 GFX_EXPORT Point ScaleToFlooredPoint(const Point& point, float x_scale);
 GFX_EXPORT Point ScaleToRoundedPoint(const Point& point,
                                      float x_scale,
                                      float y_scale);
 GFX_EXPORT Point ScaleToRoundedPoint(const Point& point, float x_scale);
 
 }  // namespace gfx
 
 #endif  // UI_GFX_GEOMETRY_POINT_H_