dark_mode: Live updae the time view and logout button in status area.

Bug: 1131543
Change-Id: Ib6f4f7ddf5efec27ad42bba135ee0e9478bf2147
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2542043Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Min Chen <minch@chromium.org>
Cr-Commit-Position: refs/heads/master@{#827906}

ash/system/session/logout_button_tray.cc

@@ -35,15 +35,12 @@ LogoutButtonTray::LogoutButtonTray(Shelf* shelf) : TrayBackgroundView(shelf) {
   DCHECK(shelf);
   Shell::Get()->session_controller()->AddObserver(this);
 
-  auto button = std::make_unique<views::MdTextButton>(
+  button_ =
+      tray_container()->AddChildView(std::make_unique<views::MdTextButton>(
           base::BindRepeating(&LogoutButtonTray::ButtonPressed,
                               base::Unretained(this)),
-      base::string16(), CONTEXT_LAUNCHER_BUTTON);
-  button->SetProminent(true);
-  button->SetBgColorOverride(AshColorProvider::Get()->GetControlsLayerColor(
-      AshColorProvider::ControlsLayerType::kControlBackgroundColorAlert));
-
-  button_ = tray_container()->AddChildView(std::move(button));
+          base::string16(), CONTEXT_LAUNCHER_BUTTON));
+  button_->SetProminent(true);
 }
 
 LogoutButtonTray::~LogoutButtonTray() {
@@ -89,6 +86,12 @@ const char* LogoutButtonTray::GetClassName() const {
   return "LogoutButtonTray";
 }
 
+void LogoutButtonTray::OnThemeChanged() {
+  TrayBackgroundView::OnThemeChanged();
+  button_->SetBgColorOverride(AshColorProvider::Get()->GetControlsLayerColor(
+      AshColorProvider::ControlsLayerType::kControlBackgroundColorAlert));
+}
+
 void LogoutButtonTray::UpdateShowLogoutButtonInTray() {
   show_logout_button_in_tray_ = pref_change_registrar_->prefs()->GetBoolean(
       prefs::kShowLogoutButtonInTray);

ash/system/session/logout_button_tray.h

@@ -44,6 +44,7 @@ class ASH_EXPORT LogoutButtonTray : public TrayBackgroundView,
   base::string16 GetAccessibleNameForTray() override;
   void HandleLocaleChange() override;
   const char* GetClassName() const override;
+  void OnThemeChanged() override;
 
   // SessionObserver:
   void OnActiveUserPrefServiceChanged(PrefService* prefs) override;

ash/system/time/time_tray_item_view.cc

@@ -4,6 +4,7 @@
 
 #include "ash/system/time/time_tray_item_view.h"
 
+#include "ash/session/session_controller_impl.h"
 #include "ash/shelf/shelf.h"
 #include "ash/shell.h"
 #include "ash/system/model/clock_model.h"
@@ -47,5 +48,11 @@ const char* TimeTrayItemView::GetClassName() const {
   return "TimeTrayItemView";
 }
 
+void TimeTrayItemView::OnThemeChanged() {
+  TrayItemView::OnThemeChanged();
+  time_view_->SetTextColor(
+      TrayIconColor(Shell::Get()->session_controller()->GetSessionState()));
+}
+
 }  // namespace tray
 }  // namespace ash

ash/system/time/time_tray_item_view.h

@@ -33,6 +33,7 @@ class TimeTrayItemView : public TrayItemView, public SessionObserver {
 
   // views::View:
   const char* GetClassName() const override;
+  void OnThemeChanged() override;
 
  private:
   TimeView* time_view_ = nullptr;