Add old_state parameter to CustomButton::StateChanged

ui/views/controls/button/custom_button.cc

 // Copyright (c) 2012 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 "ui/views/controls/button/custom_button.h"
 
 #include "ui/accessibility/ax_node_data.h"
 #include "ui/events/event.h"
 #include "ui/events/event_utils.h"
 #include "ui/events/keycodes/keyboard_codes.h"
@@ skipping 82 matching lines @@
       hover_animation_.Reset();
     } else if (state_ == STATE_NORMAL) {
       // For NORMAL -> HOVERED, animate from not hovered (0) to hovered (1).
       hover_animation_.Show();
     } else {
       // For PRESSED/DISABLED -> HOVERED, simply set the state to hovered (1).
       hover_animation_.Reset(1);
     }
   }
 
+  ButtonState old_state = state_;
   state_ = state;
-  StateChanged();
+  StateChanged(old_state);
   SchedulePaint();
 }
 
 void CustomButton::StartThrobbing(int cycles_til_stop) {
   if (!animate_on_state_change_)
     return;
   is_throbbing_ = true;
   hover_animation_.StartThrobbing(cycles_til_stop);
 }
 
@@ skipping 315 matching lines @@
       is_throbbing_(false),
       triggerable_event_flags_(ui::EF_LEFT_MOUSE_BUTTON),
       request_focus_on_press_(false),
       notify_action_(NOTIFY_ON_RELEASE),
       has_ink_drop_action_on_click_(false),
       hide_ink_drop_when_showing_context_menu_(true),
       ink_drop_base_color_(gfx::kPlaceholderColor) {
   hover_animation_.SetSlideDuration(kHoverFadeDurationMs);
 }
 
-void CustomButton::StateChanged() {
-}
+void CustomButton::StateChanged(ButtonState old_state) {}
 
 bool CustomButton::IsTriggerableEvent(const ui::Event& event) {
   return event.type() == ui::ET_GESTURE_TAP_DOWN ||
          event.type() == ui::ET_GESTURE_TAP ||
          (event.IsMouseEvent() &&
              (triggerable_event_flags_ & event.flags()) != 0);
 }
 
 bool CustomButton::ShouldEnterPushedState(const ui::Event& event) {
   return IsTriggerableEvent(event);
@@ skipping 39 matching lines @@
           views::InkDropState::ACTION_PENDING ||
       GetInkDrop()->GetTargetInkDropState() ==
           views::InkDropState::ALTERNATE_ACTION_PENDING) {
     AnimateInkDrop(views::InkDropState::HIDDEN,
                    ui::LocatedEvent::FromIfValid(&event));
   }
   Button::OnClickCanceled(event);
 }
 
 }  // namespace views