CrOS shelf: make control buttons inherit from Button, not ImageButton

This is the first step of an effort to de-duplicate some code between
ShelfButton, AppListButton, BackButton, ShelfControlButton.

This makes the class inheritance of ShelfControlButton a lot closer to
ShelfButton. None of the functionality of ImageButton is used anyway,
so inheriting from plain Button directly makes more sense.

Bug: 714781
Change-Id: I20cdc87b39a82ea70813ca7492df79890a255126
Reviewed-on: https://chromium-review.googlesource.com/c/1395565Reviewed-by: Xiyuan Xia <xiyuan@chromium.org>
Commit-Queue: Manu Cornet <manucornet@chromium.org>
Cr-Commit-Position: refs/heads/master@{#619992}

ash/shelf/app_list_button.cc

@@ -124,10 +124,10 @@ void AppListButton::OnGestureEvent(ui::GestureEvent* event) {
       if (!Shell::Get()->app_list_controller()->IsVisible() || IsTabletMode())
         AnimateInkDrop(views::InkDropState::ACTION_TRIGGERED, event);
 
-      ImageButton::OnGestureEvent(event);
+      Button::OnGestureEvent(event);
       return;
     case ui::ET_GESTURE_TAP_DOWN:
-      // If |!ShouldEnterPushedState|, ImageButton::OnGestureEvent will not set
+      // If |!ShouldEnterPushedState|, Button::OnGestureEvent will not set
       // the event to be handled. This will cause the |ET_GESTURE_TAP| or
       // |ET_GESTURE_TAP_CANCEL| not to be sent to |app_list_button|, therefore
       // leaving the assistant overlay ripple stays visible.
@@ -145,7 +145,7 @@ void AppListButton::OnGestureEvent(ui::GestureEvent* event) {
       if (!Shell::Get()->app_list_controller()->IsVisible() || IsTabletMode())
         AnimateInkDrop(views::InkDropState::ACTION_PENDING, event);
 
-      ImageButton::OnGestureEvent(event);
+      Button::OnGestureEvent(event);
       // If assistant overlay animation starts, we need to make sure the event
       // is handled in order to end the animation in |ET_GESTURE_TAP| or
       // |ET_GESTURE_TAP_CANCEL|.
@@ -166,7 +166,7 @@ void AppListButton::OnGestureEvent(ui::GestureEvent* event) {
           Shell::Get()->app_list_controller()->StartVoiceInteractionSession();
         }
       } else {
-        ImageButton::OnGestureEvent(event);
+        Button::OnGestureEvent(event);
       }
       return;
     case ui::ET_GESTURE_LONG_TAP:
@@ -177,33 +177,33 @@ void AppListButton::OnGestureEvent(ui::GestureEvent* event) {
         AnimateInkDrop(views::InkDropState::HIDDEN, event);
         event->SetHandled();
       } else {
-        ImageButton::OnGestureEvent(event);
+        Button::OnGestureEvent(event);
       }
       return;
     default:
-      ImageButton::OnGestureEvent(event);
+      Button::OnGestureEvent(event);
       return;
   }
 }
 
 bool AppListButton::OnMousePressed(const ui::MouseEvent& event) {
-  ImageButton::OnMousePressed(event);
+  Button::OnMousePressed(event);
   shelf_view_->PointerPressedOnButton(this, ShelfView::MOUSE, event);
   return true;
 }
 
 void AppListButton::OnMouseReleased(const ui::MouseEvent& event) {
-  ImageButton::OnMouseReleased(event);
+  Button::OnMouseReleased(event);
   shelf_view_->PointerReleasedOnButton(this, ShelfView::MOUSE, false);
 }
 
 void AppListButton::OnMouseCaptureLost() {
   shelf_view_->PointerReleasedOnButton(this, ShelfView::MOUSE, true);
-  ImageButton::OnMouseCaptureLost();
+  Button::OnMouseCaptureLost();
 }
 
 bool AppListButton::OnMouseDragged(const ui::MouseEvent& event) {
-  ImageButton::OnMouseDragged(event);
+  Button::OnMouseDragged(event);
   shelf_view_->PointerDraggedOnButton(this, ShelfView::MOUSE, event);
   return true;
 }
@@ -227,7 +227,7 @@ std::unique_ptr<views::InkDropRipple> AppListButton::CreateInkDropRipple()
 }
 
 void AppListButton::NotifyClick(const ui::Event& event) {
-  ImageButton::NotifyClick(event);
+  Button::NotifyClick(event);
   if (listener_)
     listener_->ButtonPressed(this, event, GetInkDrop());
 }
@@ -235,7 +235,7 @@ void AppListButton::NotifyClick(const ui::Event& event) {
 bool AppListButton::ShouldEnterPushedState(const ui::Event& event) {
   if (!shelf_view_->ShouldEventActivateButton(this, event))
     return false;
-  return views::ImageButton::ShouldEnterPushedState(event);
+  return views::Button::ShouldEnterPushedState(event);
 }
 
 std::unique_ptr<views::InkDrop> AppListButton::CreateInkDrop() {

ash/shelf/app_list_button.h

@@ -15,7 +15,6 @@
 #include "ash/shell_observer.h"
 #include "base/macros.h"
 #include "third_party/skia/include/core/SkColor.h"
-#include "ui/views/controls/button/image_button.h"
 
 namespace base {
 class OneShotTimer;

ash/shelf/back_button.cc

@@ -34,7 +34,7 @@ BackButton::BackButton() : ShelfControlButton() {
 BackButton::~BackButton() = default;
 
 void BackButton::OnGestureEvent(ui::GestureEvent* event) {
-  ImageButton::OnGestureEvent(event);
+  Button::OnGestureEvent(event);
   if (event->type() == ui::ET_GESTURE_TAP ||
       event->type() == ui::ET_GESTURE_TAP_DOWN) {
     GenerateAndSendBackEvent(event->type());
@@ -42,13 +42,13 @@ void BackButton::OnGestureEvent(ui::GestureEvent* event) {
 }
 
 bool BackButton::OnMousePressed(const ui::MouseEvent& event) {
-  ImageButton::OnMousePressed(event);
+  Button::OnMousePressed(event);
   GenerateAndSendBackEvent(event.type());
   return true;
 }
 
 void BackButton::OnMouseReleased(const ui::MouseEvent& event) {
-  ImageButton::OnMouseReleased(event);
+  Button::OnMouseReleased(event);
   GenerateAndSendBackEvent(event.type());
 }
 

ash/shelf/back_button.h

@@ -10,7 +10,6 @@
 #include "ash/ash_export.h"
 #include "ash/shelf/shelf_control_button.h"
 #include "base/macros.h"
-#include "ui/views/controls/button/image_button.h"
 
 namespace ash {
 
@@ -23,7 +22,7 @@ class ASH_EXPORT BackButton : public ShelfControlButton {
   ~BackButton() override;
 
  protected:
-  // views::ImageButton:
+  // views::Button:
   void OnGestureEvent(ui::GestureEvent* event) override;
   bool OnMousePressed(const ui::MouseEvent& event) override;
   void OnMouseReleased(const ui::MouseEvent& event) override;

ash/shelf/shelf_control_button.cc

@@ -17,7 +17,7 @@
 
 namespace ash {
 
-ShelfControlButton::ShelfControlButton() : views::ImageButton(nullptr) {
+ShelfControlButton::ShelfControlButton() : views::Button(nullptr) {
   SetInkDropMode(InkDropMode::ON_NO_GESTURE_HANDLER);
   set_has_ink_drop_action_on_click(true);
   set_ink_drop_base_color(kShelfInkDropBaseColor);

ash/shelf/shelf_control_button.h

@@ -9,13 +9,13 @@
 
 #include "ash/ash_export.h"
 #include "base/macros.h"
-#include "ui/views/controls/button/image_button.h"
+#include "ui/views/controls/button/button.h"
 
 namespace ash {
 
 // Base class for controls shown on the shelf that are not app shortcuts, such
 // as the app list, back, and overflow buttons.
-class ASH_EXPORT ShelfControlButton : public views::ImageButton {
+class ASH_EXPORT ShelfControlButton : public views::Button {
  public:
   ShelfControlButton();
   ~ShelfControlButton() override;
@@ -25,7 +25,7 @@ class ASH_EXPORT ShelfControlButton : public views::ImageButton {
   gfx::Point GetCenterPoint() const;
 
  protected:
-  // views::ImageButton:
+  // views::Button:
   std::unique_ptr<views::InkDropRipple> CreateInkDropRipple() const override;
   std::unique_ptr<views::InkDrop> CreateInkDrop() override;
   std::unique_ptr<views::InkDropMask> CreateInkDropMask() const override;