Change FocusSynchronizer to maintain active focus client and window.

ui/aura/env.cc

Index: ui/aura/env.cc
diff --git a/ui/aura/env.cc b/ui/aura/env.cc
index 9436b2be50f4a95bc40322d8bef9a0a43b4b202c..115f7e5f18809bec56953dc354c0659d54fff79e 100644
--- a/ui/aura/env.cc
+++ b/ui/aura/env.cc
@@ -9,7 +9,6 @@
 #include "base/memory/ptr_util.h"
 #include "base/threading/thread_local.h"
 #include "ui/aura/client/aura_constants.h"
-#include "ui/aura/client/focus_client.h"
 #include "ui/aura/env_observer.h"
 #include "ui/aura/input_state_lookup.h"
 #include "ui/aura/mus/mus_types.h"
@@ -17,7 +16,6 @@
 #include "ui/aura/mus/window_port_mus.h"
 #include "ui/aura/mus/window_tree_client.h"
 #include "ui/aura/window.h"
-#include "ui/aura/window_observer.h"
 #include "ui/aura/window_port_local.h"
 #include "ui/events/event_target_iterator.h"
 #include "ui/events/platform/platform_event_source.h"
@@ -42,36 +40,6 @@ bool RunningInsideMus() {
 
 }  // namespace
 
-// Observes destruction and changes of the FocusClient for a window.
-// ActiveFocusClientWindowObserver is created for the window the FocusClient is
-// associated with.
-class Env::ActiveFocusClientWindowObserver : public WindowObserver {
- public:
-  explicit ActiveFocusClientWindowObserver(Window* window) : window_(window) {
-    window_->AddObserver(this);
-  }
-  ~ActiveFocusClientWindowObserver() override { window_->RemoveObserver(this); }
-
-  // WindowObserver:
-  void OnWindowDestroying(Window* window) override {
-    Env::GetInstance()->OnActiveFocusClientWindowDestroying();
-  }
-  void OnWindowPropertyChanged(Window* window,
-                               const void* key,
-                               intptr_t old) override {
-    if (key != client::kFocusClientKey)
-      return;
-
-    // Assume if the focus client changes the window is being destroyed.
-    Env::GetInstance()->OnActiveFocusClientWindowDestroying();
-  }
-
- private:
-  Window* window_;
-
-  DISALLOW_COPY_AND_ASSIGN(ActiveFocusClientWindowObserver);
-};
-
 ////////////////////////////////////////////////////////////////////////////////
 // Env, public:
 
@@ -162,24 +130,6 @@ void Env::SetWindowTreeClient(WindowTreeClient* window_tree_client) {
   window_tree_client_ = window_tree_client;
 }
 
-void Env::SetActiveFocusClient(client::FocusClient* focus_client,
-                               Window* focus_client_root) {
-  if (focus_client == active_focus_client_ &&
-      focus_client_root == active_focus_client_root_) {
-    return;
-  }
-
-  active_focus_client_window_observer_.reset();
-  active_focus_client_ = focus_client;
-  active_focus_client_root_ = focus_client_root;
-  if (focus_client_root) {
-    active_focus_client_window_observer_ =
-        base::MakeUnique<ActiveFocusClientWindowObserver>(focus_client_root);
-  }
-  for (EnvObserver& observer : observers_)
-    observer.OnActiveFocusClientChanged(focus_client, focus_client_root);
-}
-
 ////////////////////////////////////////////////////////////////////////////////
 // Env, private:
 
@@ -233,10 +183,6 @@ void Env::NotifyHostActivated(WindowTreeHost* host) {
     observer.OnHostActivated(host);
 }
 
-void Env::OnActiveFocusClientWindowDestroying() {
-  SetActiveFocusClient(nullptr, nullptr);
-}
-
 ////////////////////////////////////////////////////////////////////////////////
 // Env, ui::EventTarget implementation: