CrOS systray: Remove some unused code paths (root window observing)

Change-Id: Icab080ad2cffd4b0e46c4075c2bb0c23beca9e2f
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2079254Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Manu Cornet <manucornet@chromium.org>
Cr-Commit-Position: refs/heads/master@{#745482}

ash/system/tray/tray_background_view.cc

@@ -353,12 +353,6 @@ void TrayBackgroundView::UpdateAfterLoginStatusChange() {
   // Handled in subclasses.
 }
 
-void TrayBackgroundView::UpdateAfterRootWindowBoundsChange(
-    const gfx::Rect& old_bounds,
-    const gfx::Rect& new_bounds) {
-  // Do nothing by default. Child class may do something.
-}
-
 void TrayBackgroundView::UpdateAfterStatusAreaCollapseChange() {
   // We call the base class' SetVisible to skip animations.
   views::View::SetVisible(GetEffectiveVisibility());

ash/system/tray/tray_background_view.h

@@ -73,10 +73,6 @@ class ASH_EXPORT TrayBackgroundView : public ActionableView,
   // Called to update the tray button after the login status changes.
   virtual void UpdateAfterLoginStatusChange();
 
-  // Called whenever the bounds of the root window changes.
-  virtual void UpdateAfterRootWindowBoundsChange(const gfx::Rect& old_bounds,
-                                                 const gfx::Rect& new_bounds);
-
   // Called whenever the status area's collapse state changes.
   virtual void UpdateAfterStatusAreaCollapseChange();
 

ash/system/tray/tray_bubble_wrapper.cc

@@ -29,8 +29,6 @@ TrayBubbleWrapper::TrayBubbleWrapper(TrayBackgroundView* tray,
 
   tray->tray_event_filter()->AddBubble(this);
 
-  bubble_widget_->GetNativeWindow()->GetRootWindow()->AddObserver(this);
-
   if (!is_persistent_)
     Shell::Get()->activation_client()->AddObserver(this);
 }
@@ -47,7 +45,6 @@ TrayBubbleWrapper::~TrayBubbleWrapper() {
       for (auto* window : transient_manager->transient_children())
         transient_manager->RemoveTransientChild(window);
     }
-    bubble_widget_->GetNativeWindow()->GetRootWindow()->RemoveObserver(this);
     bubble_widget_->RemoveObserver(this);
     bubble_widget_->Close();
   }
@@ -65,13 +62,6 @@ views::Widget* TrayBubbleWrapper::GetBubbleWidget() const {
   return bubble_widget_;
 }
 
-void TrayBubbleWrapper::OnWidgetClosing(views::Widget* widget) {
-  CHECK_EQ(bubble_widget_, widget);
-  // Remove this from the observer list before the widget is closed and detached
-  // from the root window.
-  bubble_widget_->GetNativeWindow()->GetRootWindow()->RemoveObserver(this);
-}
-
 void TrayBubbleWrapper::OnWidgetDestroying(views::Widget* widget) {
   CHECK_EQ(bubble_widget_, widget);
   bubble_widget_->RemoveObserver(this);
@@ -92,13 +82,6 @@ void TrayBubbleWrapper::OnWidgetBoundsChanged(views::Widget* widget,
   tray_->BubbleResized(bubble_view_);
 }
 
-void TrayBubbleWrapper::OnWindowBoundsChanged(aura::Window* window,
-                                              const gfx::Rect& old_bounds,
-                                              const gfx::Rect& new_bounds,
-                                              ui::PropertyChangeReason reason) {
-  tray_->UpdateAfterRootWindowBoundsChange(old_bounds, new_bounds);
-}
-
 void TrayBubbleWrapper::OnWindowActivated(ActivationReason reason,
                                           aura::Window* gained_active,
                                           aura::Window* lost_active) {

ash/system/tray/tray_bubble_wrapper.h

@@ -8,7 +8,6 @@
 #include "ash/ash_export.h"
 #include "ash/system/tray/tray_bubble_base.h"
 #include "base/macros.h"
-#include "ui/aura/window_observer.h"
 #include "ui/views/widget/widget_observer.h"
 #include "ui/wm/public/activation_change_observer.h"
 
@@ -21,7 +20,6 @@ class TrayBubbleView;
 // TODO(tetsui): Remove this and use TrayBubbleBase for all bubbles.
 class ASH_EXPORT TrayBubbleWrapper : public TrayBubbleBase,
                                      public views::WidgetObserver,
-                                     public aura::WindowObserver,
                                      public ::wm::ActivationChangeObserver {
  public:
   TrayBubbleWrapper(TrayBackgroundView* tray,
@@ -35,17 +33,10 @@ class ASH_EXPORT TrayBubbleWrapper : public TrayBubbleBase,
   views::Widget* GetBubbleWidget() const override;
 
   // views::WidgetObserver overrides:
-  void OnWidgetClosing(views::Widget* widget) override;
   void OnWidgetDestroying(views::Widget* widget) override;
   void OnWidgetBoundsChanged(views::Widget* widget,
                              const gfx::Rect& new_bounds) override;
 
-  // aura::WindowObserver:
-  void OnWindowBoundsChanged(aura::Window* window,
-                             const gfx::Rect& old_bounds,
-                             const gfx::Rect& new_bounds,
-                             ui::PropertyChangeReason reason) override;
-
   // ::wm::ActivationChangeObserver overrides:
   void OnWindowActivated(ActivationReason reason,
                          aura::Window* gained_active,