Revert of chromeos: Makes mushrome use simplified display management

ash/mus/test/wm_test_helper.cc

Index: ash/mus/test/wm_test_helper.cc
diff --git a/ash/mus/test/wm_test_helper.cc b/ash/mus/test/wm_test_helper.cc
index 26bb271f6dd9908e337f648543f65fde2e0eeb57..1fd4685c7d37355c285b4574e8ba616c7a0a7497 100644
--- a/ash/mus/test/wm_test_helper.cc
+++ b/ash/mus/test/wm_test_helper.cc
@@ -8,7 +8,6 @@
 #include "ash/mus/window_manager.h"
 #include "ash/mus/window_manager_application.h"
 #include "ash/public/cpp/config.h"
-#include "ash/shell.h"
 #include "ash/test/test_shell_delegate.h"
 #include "ash/wm_window.h"
 #include "base/memory/ptr_util.h"
@@ -27,7 +26,6 @@
 #include "ui/display/display.h"
 #include "ui/display/display_list.h"
 #include "ui/display/screen_base.h"
-#include "ui/display/test/display_manager_test_api.h"
 #include "ui/views/test/test_views_delegate.h"
 
 namespace ash {
@@ -75,11 +73,6 @@
 WmTestHelper::WmTestHelper() {}
 
 WmTestHelper::~WmTestHelper() {
-  // Flush the message loop so that any pending tasks are run. This ensures
-  // any delayed tasks, such as deleting RootWindowControllers, are processed
-  // before continuing.
-  base::RunLoop().RunUntilIdle();
-
   // Needs to be destroyed before material design.
   window_manager_app_.reset();
 
@@ -106,9 +99,7 @@
 
   views_delegate_ = base::MakeUnique<views::TestViewsDelegate>();
 
-  const bool show_primary_host_on_connect = false;
-  window_manager_app_ = base::MakeUnique<WindowManagerApplication>(
-      show_primary_host_on_connect, config);
+  window_manager_app_ = base::MakeUnique<WindowManagerApplication>();
 
   message_loop_.reset(new base::MessageLoopForUI());
 
@@ -117,8 +108,8 @@
   blocking_pool_owner_ = base::MakeUnique<base::SequencedWorkerPoolOwner>(
       kMaxNumberThreads, kThreadNamePrefix);
 
-  window_manager_app_->window_manager_ = base::MakeUnique<WindowManager>(
-      nullptr, config, show_primary_host_on_connect);
+  window_manager_app_->window_manager_ =
+      base::MakeUnique<WindowManager>(nullptr, config);
   window_manager_app_->window_manager()->shell_delegate_ =
       base::MakeUnique<test::TestShellDelegate>();
 
@@ -138,12 +129,8 @@
       window_manager_app_->window_manager()->window_tree_client();
   window_tree_client_private_ =
       base::MakeUnique<aura::WindowTreeClientPrivate>(window_tree_client);
-  if (config == Config::MUS) {
-    window_tree_client_private_->CallOnConnect();
-  } else {
-    int next_x = 0;
-    CreateRootWindowController("800x600", &next_x);
-  }
+  int next_x = 0;
+  CreateRootWindowController("800x600", &next_x);
 }
 
 std::vector<RootWindowController*> WmTestHelper::GetRootsOrderedByDisplayId() {
@@ -156,11 +143,6 @@
 }
 
 void WmTestHelper::UpdateDisplay(const std::string& display_spec) {
-  if (Shell::GetAshConfig() == Config::MUS) {
-    display::test::DisplayManagerTestApi(Shell::Get()->display_manager())
-        .UpdateDisplay(display_spec);
-    return;
-  }
   const std::vector<std::string> parts = base::SplitString(
       display_spec, ",", base::TRIM_WHITESPACE, base::SPLIT_WANT_ALL);
   std::vector<RootWindowController*> root_window_controllers =