chromeos: Makes AshTestBase/Helper target mash when appropriate

ui/display/test/display_manager_test_api.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/display/test/display_manager_test_api.h"
 
 #include <cstdarg>
 #include <vector>
 
 #include "base/strings/string_split.h"
@@ skipping 40 matching lines @@
                      return mode->ui_scale() == ui_scale;
                    });
   if (iter == modes.end())
     return scoped_refptr<ManagedDisplayMode>();
   return *iter;
 }
 
 }  // namespace
 
 DisplayManagerTestApi::DisplayManagerTestApi(DisplayManager* display_manager)
-    : display_manager_(display_manager) {}
+    : display_manager_(display_manager) {
+  DCHECK(display_manager);
+}
 
 DisplayManagerTestApi::~DisplayManagerTestApi() {}
 
 void DisplayManagerTestApi::UpdateDisplay(const std::string& display_specs) {
   DisplayInfoList display_info_list =
       CreateDisplayInfoListFromString(display_specs, display_manager_);
   bool is_host_origin_set = false;
   for (size_t i = 0; i < display_info_list.size(); ++i) {
     const ManagedDisplayInfo& display_info = display_info_list[i];
     if (display_info.bounds_in_native().origin() != gfx::Point(0, 0)) {
@@ skipping 127 matching lines @@
   for (size_t i = 0; i < count; i++) {
     int64_t id = va_arg(args, int64_t);
     list.push_back(id);
   }
   SortDisplayIdList(&list);
   return list;
 }
 
 }  // namespace test
 }  // namespace display