Use list instead of pair to represent the set of displays.

chrome/browser/chromeos/policy/display_rotation_default_handler_browsertest.cc

 // Copyright 2015 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 <stdint.h>
 
 #include "ash/display/display_manager.h"
 #include "ash/shell.h"
 #include "base/bind.h"
 #include "base/command_line.h"
@@ skipping 38 matching lines @@
 }
 
 // Fails the test and returns ROTATE_0 if there is no second display.
 gfx::Display::Rotation GetRotationOfSecondDisplay() {
   const ash::DisplayManager* const display_manager = GetDisplayManager();
   if (display_manager->GetNumDisplays() < 2) {
     ADD_FAILURE()
         << "Requested rotation of second display while there was only one.";
     return gfx::Display::ROTATE_0;
   }
-  const ash::DisplayIdPair display_id_pair =
-      display_manager->GetCurrentDisplayIdPair();
+  const ash::DisplayIdList display_id_pair =
+      display_manager->GetCurrentDisplayIdList();
   const gfx::Display& second_display =
-      display_manager->GetDisplayForId(display_id_pair.second);
+      display_manager->GetDisplayForId(display_id_pair[1]);
   return second_display.rotation();
 }
 
 } // anonymous namespace
 
 namespace policy {
 
 class DisplayRotationDefaultTest
     : public policy::DevicePolicyCrosBrowserTest,
       public testing::WithParamInterface<gfx::Display::Rotation> {
@@ skipping 248 matching lines @@
 }
 
 INSTANTIATE_TEST_CASE_P(PolicyDisplayRotationDefault,
                         DisplayRotationBootTest,
                         testing::Values(gfx::Display::ROTATE_0,
                                         gfx::Display::ROTATE_90,
                                         gfx::Display::ROTATE_180,
                                         gfx::Display::ROTATE_270));
 
 }  // namespace policy