chromeos: Remove AshTestBase::SupportsMultipleDisplays

ash/mus/test/wm_test_base.cc

 // Copyright 2016 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 "ash/mus/test/wm_test_base.h"
 
 #include <algorithm>
 #include <vector>
 
 #include "ash/common/session/session_controller.h"
@@ skipping 50 matching lines @@
 
 WmTestBase::WmTestBase() {}
 
 WmTestBase::~WmTestBase() {
   CHECK(setup_called_)
       << "You have overridden SetUp but never called WmTestBase::SetUp";
   CHECK(teardown_called_)
       << "You have overridden TearDown but never called WmTestBase::TearDown";
 }
 
-bool WmTestBase::SupportsMultipleDisplays() const {
-  return true;
-}
-
 void WmTestBase::UpdateDisplay(const std::string& display_spec) {
   test_helper_->UpdateDisplay(display_spec);
 }
 
 aura::Window* WmTestBase::GetPrimaryRootWindow() {
   std::vector<RootWindowController*> roots =
       test_helper_->GetRootsOrderedByDisplayId();
   DCHECK(!roots.empty());
   return roots[0]->GetRootWindow();
 }
@@ skipping 117 matching lines @@
   info->can_lock_screen = true;
   info->should_lock_screen_automatically = false;
   info->add_user_session_policy = AddUserSessionPolicy::ALLOWED;
   info->state = session_manager::SessionState::ACTIVE;
   session_controller->SetSessionInfo(std::move(info));
 }
 
 
 }  // namespace mus
 }  // namespace ash