Add missing operator<() to CFX_RetainPtr

core/fxcrt/cfx_retain_ptr_unittest.cpp

 // Copyright 2016 PDFium 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 "core/fxcrt/cfx_retain_ptr.h"
 
 #include <utility>
 
 #include "testing/fx_string_testhelpers.h"
 #include "testing/gtest/include/gtest/gtest.h"
@@ skipping 207 matching lines @@
     CFX_RetainPtr<PseudoRetainable> obj2_ptr2(&obj2);
     EXPECT_FALSE(null_ptr1 != null_ptr2);
     EXPECT_FALSE(obj1_ptr1 != obj1_ptr2);
     EXPECT_FALSE(obj2_ptr1 != obj2_ptr2);
   }
   EXPECT_TRUE(null_ptr1 != obj1_ptr1);
   EXPECT_TRUE(null_ptr1 != obj2_ptr1);
   EXPECT_TRUE(obj1_ptr1 != obj2_ptr1);
 }
 
+TEST(fxcrt, RetainPtrLessThan) {
+  PseudoRetainable objs[2];
+  CFX_RetainPtr<PseudoRetainable> obj1_ptr(&objs[0]);
+  CFX_RetainPtr<PseudoRetainable> obj2_ptr(&objs[1]);
+  EXPECT_TRUE(obj1_ptr < obj2_ptr);
+  EXPECT_FALSE(obj2_ptr < obj1_ptr);
+}
+
 TEST(fxcrt, RetainPtrBool) {
   PseudoRetainable obj1;
   CFX_RetainPtr<PseudoRetainable> null_ptr;
   CFX_RetainPtr<PseudoRetainable> obj1_ptr(&obj1);
   bool null_bool = !!null_ptr;
   bool obj1_bool = !!obj1_ptr;
   EXPECT_FALSE(null_bool);
   EXPECT_TRUE(obj1_bool);
 }
 
 TEST(fxcrt, RetainPtrMakeRetained) {
   auto ptr = pdfium::MakeRetain<CFX_Retainable>();
   EXPECT_TRUE(ptr->HasOneRef());
   {
     CFX_RetainPtr<CFX_Retainable> other = ptr;
     EXPECT_FALSE(ptr->HasOneRef());
   }
   EXPECT_TRUE(ptr->HasOneRef());
 }