Removed gfx::QuadF::operator =(const gfx::QuadF&) and let the compiler generate one

ui/gfx/quad_f.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 "ui/gfx/quad_f.h"
 
 #include <cmath>
 #include <limits>
 
 #include "base/stringprintf.h"
 
 namespace gfx {
 
-void QuadF::operator=(const QuadF& quad) {
-  p1_ = quad.p1_;
-  p2_ = quad.p2_;
-  p3_ = quad.p3_;
-  p4_ = quad.p4_;
-}
-
 void QuadF::operator=(const RectF& rect) {
   p1_ = PointF(rect.x(), rect.y());
   p2_ = PointF(rect.right(), rect.y());
   p3_ = PointF(rect.right(), rect.bottom());
   p4_ = PointF(rect.x(), rect.bottom());
 }
 
 std::string QuadF::ToString() const {
   return base::StringPrintf("%s;%s;%s;%s",
                             p1_.ToString().c_str(),
@@ skipping 103 matching lines @@
   return result;
 }
 
 QuadF operator-(const QuadF& lhs, const Vector2dF& rhs) {
   QuadF result = lhs;
   result -= rhs;
   return result;
 }
 
 }  // namespace gfx