views: Remove dead code in CustomButton.

CustomButtonStateChangedDelegate was itnroduced in http://crrev.com/159994, and
its use was removed in http://crrev.com/185369 It hasn't been used since. So
remove the code.

BUG=none
R=tfarina@chromium.org

Review URL: https://codereview.chromium.org/872473004

Cr-Commit-Position: refs/heads/master@{#313515}

ui/views/controls/button/custom_button.cc

@@ -73,8 +73,6 @@ void CustomButton::SetState(ButtonState state) {
 
   state_ = state;
   StateChanged();
-  if (state_changed_delegate_.get())
-    state_changed_delegate_->StateChanged(state_);
   SchedulePaint();
 }
 

ui/views/controls/button/custom_button.h

@@ -16,8 +16,6 @@ class ThrobAnimation;
 
 namespace views {
 
-class CustomButtonStateChangedDelegate;
-
 // A button with custom rendering. The base of ImageButton and LabelButton.
 // Note that this type of button is not focusable by default and will not be
 // part of the focus chain.  Call SetFocusable(true) to make it part of the
@@ -89,11 +87,6 @@ class VIEWS_EXPORT CustomButton : public Button,
   // Overridden from gfx::AnimationDelegate:
   void AnimationProgressed(const gfx::Animation* animation) override;
 
-  // Takes ownership of the delegate.
-  void set_state_changed_delegate(CustomButtonStateChangedDelegate* delegate) {
-    state_changed_delegate_.reset(delegate);
-  }
-
  protected:
   // Construct the Button with a Listener. See comment for Button's ctor.
   explicit CustomButton(ButtonListener* listener);
@@ -137,24 +130,9 @@ class VIEWS_EXPORT CustomButton : public Button,
   // See description above setter.
   bool request_focus_on_press_;
 
-  scoped_ptr<CustomButtonStateChangedDelegate> state_changed_delegate_;
-
   DISALLOW_COPY_AND_ASSIGN(CustomButton);
 };
 
-// Delegate for actions taken on state changes by CustomButton.
-class VIEWS_EXPORT CustomButtonStateChangedDelegate {
-public:
-  virtual ~CustomButtonStateChangedDelegate() {}
-  virtual void StateChanged(Button::ButtonState state) = 0;
-
-protected:
-  CustomButtonStateChangedDelegate() {}
-
-private:
-  DISALLOW_COPY_AND_ASSIGN(CustomButtonStateChangedDelegate);
-};
-
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_BUTTON_CUSTOM_BUTTON_H_