Preserve the native mode when parsing external display modes

ash/display/display_change_observer_chromeos_unittest.cc

 // Copyright 2013 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/display/display_change_observer_chromeos.h"
 
 #include "ash/display/display_info.h"
 #include "base/memory/scoped_vector.h"
 #include "testing/gtest/include/gtest/gtest.h"
 #include "ui/display/chromeos/display_configurator.h"
@@ skipping 295 matching lines @@
   EXPECT_EQ(display_modes[7].device_scale_factor, 1.25);
 
   EXPECT_EQ("3840x2160", display_modes[8].size.ToString());
   EXPECT_FALSE(display_modes[8].interlaced);
   EXPECT_TRUE(display_modes[8].native);
   EXPECT_EQ(display_modes[8].refresh_rate, 30);
 
   // Outputs without any modes shouldn't cause a crash.
   modes.clear();
   display_snapshot.set_modes(modes.get());
+  display_snapshot.set_native_mode(NULL);
 
   display_modes = DisplayChangeObserver::GetExternalDisplayModeList(output);
   EXPECT_EQ(0u, display_modes.size());
 }
 
 TEST_F(DisplayChangeObserverTest, FindDeviceScaleFactor) {
   // 19.5" 1600x900
   EXPECT_EQ(1.0f, DisplayChangeObserver::FindDeviceScaleFactor(94.14f));
 
   // 21.5" 1920x1080
@@ skipping 10 matching lines @@
 
   // 12.85" 2560x1700
   EXPECT_EQ(2.0f, DisplayChangeObserver::FindDeviceScaleFactor(239.15f));
 
   // Erroneous values should still work.
   EXPECT_EQ(1.0f, DisplayChangeObserver::FindDeviceScaleFactor(-100.0f));
   EXPECT_EQ(1.0f, DisplayChangeObserver::FindDeviceScaleFactor(0.0f));
   EXPECT_EQ(2.0f, DisplayChangeObserver::FindDeviceScaleFactor(10000.0f));
 }
 
+TEST_F(DisplayChangeObserverTest,
+       FindExternalDisplayNativeModeWhenOverwritten) {
+  ScopedVector<const ui::DisplayMode> modes;
+  modes.push_back(new ui::DisplayMode(gfx::Size(1920, 1080), true, 60));
+  modes.push_back(new ui::DisplayMode(gfx::Size(1920, 1080), false, 60));
+
+  ui::TestDisplaySnapshot display_snapshot;
+  display_snapshot.set_modes(modes.get());
+  display_snapshot.set_native_mode(modes[0]);
+  DisplayConfigurator::DisplayState output;
+  output.display = &display_snapshot;
+
+  std::vector<DisplayMode> display_modes =
+      DisplayChangeObserver::GetExternalDisplayModeList(output);
+  ASSERT_EQ(2u, display_modes.size());
+  EXPECT_EQ("1920x1080", display_modes[0].size.ToString());
+  EXPECT_FALSE(display_modes[0].interlaced);
+  EXPECT_FALSE(display_modes[0].native);
+  EXPECT_EQ(display_modes[0].refresh_rate, 60);
+
+  EXPECT_EQ("1920x1080", display_modes[1].size.ToString());
+  EXPECT_TRUE(display_modes[1].interlaced);
+  EXPECT_TRUE(display_modes[1].native);
+  EXPECT_EQ(display_modes[1].refresh_rate, 60);
+}
+
 }  // namespace ash