dark_mode: Remove TrayBackgroundView::UpdateAfterColorModeChange.

StatusAreaWidget::UpdateAfterColorModeChange looks not color mode
related, but session state related. Make it call UpdateBackground()
directly.

Bug: 1131543
Change-Id: I858e5a3bd64cc735d547dc7fec1554f011885916
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2508169Reviewed-by: Ahmed Fakhry <afakhry@chromium.org>
Commit-Queue: Min Chen <minch@chromium.org>
Cr-Commit-Position: refs/heads/master@{#822836}

ash/system/status_area_widget.cc

@@ -187,7 +187,8 @@ void StatusAreaWidget::SetSystemTrayVisibility(bool visible) {
 
 void StatusAreaWidget::OnSessionStateChanged(
     session_manager::SessionState state) {
-  UpdateAfterColorModeChange();
+  for (TrayBackgroundView* tray_button : tray_buttons_)
+    tray_button->UpdateBackground();
 }
 
 void StatusAreaWidget::UpdateCollapseState() {
@@ -553,11 +554,6 @@ void StatusAreaWidget::OnScrollEvent(ui::ScrollEvent* event) {
     views::Widget::OnScrollEvent(event);
 }
 
-void StatusAreaWidget::UpdateAfterColorModeChange() {
-  for (TrayBackgroundView* tray_button : tray_buttons_)
-    tray_button->UpdateAfterColorModeChange();
-}
-
 void StatusAreaWidget::AddTrayButton(TrayBackgroundView* tray_button) {
   status_area_widget_delegate_->AddChildView(tray_button);
   tray_buttons_.push_back(tray_button);

ash/system/status_area_widget.h

@@ -208,9 +208,6 @@ class ASH_EXPORT StatusAreaWidget : public SessionObserver,
   // Adds a new tray button to the status area.
   void AddTrayButton(TrayBackgroundView* tray_button);
 
-  // Update the colors used for the tray buttons.
-  void UpdateAfterColorModeChange();
-
   // Called when in the collapsed state to calculate and update the visibility
   // of each tray button.
   void CalculateButtonVisibilityForCollapsedState();

ash/system/tray/tray_background_view.cc

@@ -371,13 +371,19 @@ void TrayBackgroundView::UpdateAfterStatusAreaCollapseChange() {
   views::View::SetVisible(GetEffectiveVisibility());
 }
 
-void TrayBackgroundView::UpdateAfterColorModeChange() {
-  UpdateBackground();
-  SchedulePaint();
-}
-
 void TrayBackgroundView::BubbleResized(const TrayBubbleView* bubble_view) {}
 
+void TrayBackgroundView::UpdateBackground() {
+  const int radius = ShelfConfig::Get()->control_border_radius();
+  gfx::RoundedCornersF rounded_corners = {radius, radius, radius, radius};
+  layer()->SetRoundedCornerRadius(rounded_corners);
+  layer()->SetIsFastRoundedCorner(true);
+  layer()->SetBackgroundBlur(
+      ShelfConfig::Get()->GetShelfControlButtonBlurRadius());
+  layer()->SetColor(ShelfConfig::Get()->GetShelfControlButtonColor());
+  layer()->SetClipRect(GetBackgroundBounds());
+}
+
 void TrayBackgroundView::OnImplicitAnimationsCompleted() {
   // If there is another animation in the queue, the reverse animation was
   // triggered before the completion of animating to invisible. Do not turn off
@@ -498,17 +504,6 @@ gfx::Insets TrayBackgroundView::GetBackgroundInsets() const {
   return insets;
 }
 
-void TrayBackgroundView::UpdateBackground() {
-  const int radius = ShelfConfig::Get()->control_border_radius();
-  gfx::RoundedCornersF rounded_corners = {radius, radius, radius, radius};
-  layer()->SetRoundedCornerRadius(rounded_corners);
-  layer()->SetIsFastRoundedCorner(true);
-  layer()->SetBackgroundBlur(
-      ShelfConfig::Get()->GetShelfControlButtonBlurRadius());
-  layer()->SetColor(ShelfConfig::Get()->GetShelfControlButtonColor());
-  layer()->SetClipRect(GetBackgroundBounds());
-}
-
 bool TrayBackgroundView::GetEffectiveVisibility() {
   // When the virtual keyboard is visible, the effective visibility of the view
   // is solely determined by |show_with_virtual_keyboard_|.

ash/system/tray/tray_background_view.h

@@ -76,9 +76,6 @@ class ASH_EXPORT TrayBackgroundView : public ActionableView,
   // Called whenever the status area's collapse state changes.
   virtual void UpdateAfterStatusAreaCollapseChange();
 
-  // Called whenever the system color mode changes.
-  virtual void UpdateAfterColorModeChange();
-
   // Called when the anchor (tray or bubble) may have moved or changed.
   virtual void AnchorUpdated() {}
 
@@ -101,6 +98,9 @@ class ASH_EXPORT TrayBackgroundView : public ActionableView,
   // May close the bubble.
   virtual void ClickedOutsideBubble() = 0;
 
+  // Updates the background layer.
+  virtual void UpdateBackground();
+
   void SetIsActive(bool is_active);
   bool is_active() const { return is_active_; }
 
@@ -175,9 +175,6 @@ class ASH_EXPORT TrayBackgroundView : public ActionableView,
   // Helper function that calculates background insets relative to local bounds.
   gfx::Insets GetBackgroundInsets() const;
 
-  // Updates the background layer.
-  virtual void UpdateBackground();
-
   // Returns the effective visibility of the tray item based on the current
   // state.
   bool GetEffectiveVisibility();