Add old_state parameter to CustomButton::StateChanged

ash/common/system/chromeos/audio/volume_view.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #include "ash/common/system/chromeos/audio/volume_view.h"
 
 #include <algorithm>
 
 #include "ash/common/material_design/material_design_controller.h"
 #include "ash/common/metrics/user_metrics_action.h"
@@ skipping 108 matching lines @@
   void GetAccessibleNodeData(ui::AXNodeData* node_data) override {
     ui::ResourceBundle& bundle = ui::ResourceBundle::GetSharedInstance();
     node_data->SetName(
         bundle.GetLocalizedString(IDS_ASH_STATUS_TRAY_VOLUME_MUTE));
     node_data->role = ui::AX_ROLE_TOGGLE_BUTTON;
     if (audio_delegate_->IsOutputAudioMuted())
       node_data->AddStateFlag(ui::AX_STATE_PRESSED);
   }
 
   // views::CustomButton:
-  void StateChanged() override {
+  void StateChanged(ButtonState old_state) override {
     if (state() == STATE_HOVERED || state() == STATE_PRESSED) {
       if (!MaterialDesignController::IsSystemTrayMenuMaterial()) {
         set_background(
             views::Background::CreateSolidBackground(kHoverBackgroundColor));
       }
     } else {
       set_background(nullptr);
     }
   }
 
@@ skipping 203 matching lines @@
 void VolumeView::OnBoundsChanged(const gfx::Rect& previous_bounds) {
   // Separator's prefered size is based on set bounds. When an empty bounds is
   // set on first layout this causes BoxLayout to ignore the separator. Reset
   // its height on each bounds change so that it is laid out properly.
   if (separator_)
     separator_->SetSize(gfx::Size(kSeparatorSize, bounds().height()));
 }
 
 }  // namespace tray
 }  // namespace ash