Revert of Improves focus/activation for aura-mus and DesktopNativeWidgetAura

ui/views/mus/desktop_window_tree_host_mus.cc

Index: ui/views/mus/desktop_window_tree_host_mus.cc
diff --git a/ui/views/mus/desktop_window_tree_host_mus.cc b/ui/views/mus/desktop_window_tree_host_mus.cc
index b89b191e5ddc0f112282b511648e3db7c6f1a1ae..9b11b07f8294502a1b0089c8ba97597262d55018 100644
--- a/ui/views/mus/desktop_window_tree_host_mus.cc
+++ b/ui/views/mus/desktop_window_tree_host_mus.cc
@@ -8,7 +8,6 @@
 #include "ui/aura/client/aura_constants.h"
 #include "ui/aura/client/drag_drop_client.h"
 #include "ui/aura/client/focus_client.h"
-#include "ui/aura/env.h"
 #include "ui/aura/mus/window_tree_host_mus.h"
 #include "ui/aura/window.h"
 #include "ui/display/screen.h"
@@ -30,13 +29,11 @@
       desktop_native_widget_aura_(desktop_native_widget_aura),
       fullscreen_restore_state_(ui::SHOW_STATE_DEFAULT),
       close_widget_factory_(this) {
-  aura::Env::GetInstance()->AddObserver(this);
   // TODO: use display id and bounds if available, likely need to pass in
   // InitParams for that.
 }
 
 DesktopWindowTreeHostMus::~DesktopWindowTreeHostMus() {
-  aura::Env::GetInstance()->RemoveObserver(this);
   desktop_native_widget_aura_->OnDesktopWindowTreeHostDestroyed(this);
 }
 
@@ -202,22 +199,18 @@
 }
 
 void DesktopWindowTreeHostMus::Activate() {
-  aura::Env::GetInstance()->SetActiveFocusClient(
-      aura::client::GetFocusClient(window()), window());
-  if (is_active_) {
-    window()->Focus();
-    if (window()->GetProperty(aura::client::kDrawAttentionKey))
-      window()->SetProperty(aura::client::kDrawAttentionKey, false);
-  }
+  window()->Focus();
+  if (window()->GetProperty(aura::client::kDrawAttentionKey))
+    window()->SetProperty(aura::client::kDrawAttentionKey, false);
 }
 
 void DesktopWindowTreeHostMus::Deactivate() {
-  // TODO: Deactivate() means focus next window, that needs to go to mus.
-  NOTIMPLEMENTED();
+  aura::client::GetActivationClient(window()->GetRootWindow())
+      ->DeactivateWindow(window());
 }
 
 bool DesktopWindowTreeHostMus::IsActive() const {
-  return is_active_;
+  return wm::IsActiveWindow(const_cast<aura::Window*>(window()));
 }
 
 void DesktopWindowTreeHostMus::Maximize() {
@@ -360,18 +353,4 @@
                         widget->widget_delegate()->CanResize());
 }
 
-void DesktopWindowTreeHostMus::OnWindowInitialized(aura::Window* window) {}
-
-void DesktopWindowTreeHostMus::OnActiveFocusClientChanged(
-    aura::client::FocusClient* focus_client,
-    aura::Window* window) {
-  if (window == this->window()) {
-    is_active_ = true;
-    desktop_native_widget_aura_->HandleActivationChanged(true);
-  } else if (is_active_) {
-    is_active_ = false;
-    desktop_native_widget_aura_->HandleActivationChanged(false);
-  }
-}
-
 }  // namespace views