Remove DisplayPreferencesTest tests that do not test prefs.

After earlier re-factoring, these tests no longer actually test
any code in display_preferences.cc.

Bug: none
Change-Id: Ie8d81f6efafb23918cda3af892ab48ee63cbfb29
Reviewed-on: https://chromium-review.googlesource.com/848247Reviewed-by: Weidong Guo <weidongg@chromium.org>
Commit-Queue: Steven Bennetts <stevenjb@chromium.org>
Cr-Commit-Position: refs/heads/master@{#526863}

chrome/browser/chromeos/display/display_preferences_unittest.cc

@@ -158,22 +158,6 @@ class DisplayPreferencesTest : public ash::AshTestBase {
       pref_data->Set(name, std::move(layout_value));
   }
 
-  bool GetDisplayPropertyFromList(const display::DisplayIdList& list,
-                                  const std::string& key,
-                                  base::Value** out_value) {
-    std::string name = display::DisplayIdListToString(list);
-
-    DictionaryPrefUpdate update(&local_state_, prefs::kSecondaryDisplays);
-    base::DictionaryValue* pref_data = update.Get();
-
-    base::Value* layout_value = pref_data->FindKey(name);
-    if (layout_value) {
-      return static_cast<base::DictionaryValue*>(layout_value)
-          ->Get(key, out_value);
-    }
-    return false;
-  }
-
   void StoreDisplayPropertyForList(const display::DisplayIdList& list,
                                    const std::string& key,
                                    std::unique_ptr<base::Value> value) {
@@ -1179,47 +1163,6 @@ TEST_F(DisplayPreferencesTest, RestoreThreeDisplays) {
             display_manager()->GetDisplayForId(list[2]).bounds());
 }
 
-TEST_F(DisplayPreferencesTest, MirrorWhenEnterTableMode) {
-  display::Display::SetInternalDisplayId(
-      display::Screen::GetScreen()->GetPrimaryDisplay().id());
-  LoggedInAsUser();
-  UpdateDisplay("800x600,1200x800");
-  EXPECT_FALSE(display_manager()->IsInMirrorMode());
-  ash::TabletModeController* controller =
-      ash::Shell::Get()->tablet_mode_controller();
-  controller->EnableTabletModeWindowManager(true);
-  ASSERT_TRUE(controller->IsTabletModeWindowManagerEnabled());
-  EXPECT_TRUE(display_manager()->IsInMirrorMode());
-
-  // Make sure the mirror mode is not saved in the preference.
-  display::DisplayIdList list = display_manager()->GetCurrentDisplayIdList();
-  ASSERT_EQ(2u, list.size());
-
-  // Exiting the tablet mode should exit mirror mode.
-  controller->EnableTabletModeWindowManager(false);
-  ASSERT_FALSE(controller->IsTabletModeWindowManagerEnabled());
-  EXPECT_FALSE(display_manager()->IsInMirrorMode());
-}
-
-TEST_F(DisplayPreferencesTest, AlreadyMirrorWhenEnterTableMode) {
-  display::Display::SetInternalDisplayId(
-      display::Screen::GetScreen()->GetPrimaryDisplay().id());
-  LoggedInAsUser();
-  UpdateDisplay("800x600,1200x800");
-  display_manager()->SetMirrorMode(true);
-  EXPECT_TRUE(display_manager()->IsInMirrorMode());
-  ash::TabletModeController* controller =
-      ash::Shell::Get()->tablet_mode_controller();
-  controller->EnableTabletModeWindowManager(true);
-  ASSERT_TRUE(controller->IsTabletModeWindowManagerEnabled());
-  EXPECT_TRUE(display_manager()->IsInMirrorMode());
-
-  // Exiting the tablet mode should stay in mirror mode.
-  controller->EnableTabletModeWindowManager(false);
-  ASSERT_FALSE(controller->IsTabletModeWindowManagerEnabled());
-  EXPECT_TRUE(display_manager()->IsInMirrorMode());
-}
-
 TEST_F(DisplayPreferencesTest, LegacyTouchCalibrationDataSupport) {
   UpdateDisplay("800x600,1200x800");
   LoggedInAsUser();