Move DevTools out of ash and turn it to a component.

ash/devtools/widget_element.h

-// Copyright 2017 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.
-
-#ifndef ASH_DEVTOOLS_WIDGET_ELEMENT_H_
-#define ASH_DEVTOOLS_WIDGET_ELEMENT_H_
-
-#include "ash/ash_export.h"
-#include "ash/devtools/ui_element.h"
-#include "base/macros.h"
-#include "ui/aura/window.h"
-#include "ui/gfx/geometry/rect.h"
-#include "ui/views/widget/widget.h"
-#include "ui/views/widget/widget_observer.h"
-#include "ui/views/widget/widget_removals_observer.h"
-
-namespace ash {
-namespace devtools {
-
-class UIElementDelegate;
-
-class ASH_EXPORT WidgetElement : public views::WidgetRemovalsObserver,
-                                 public views::WidgetObserver,
-                                 public UIElement {
- public:
-  WidgetElement(views::Widget* widget,
-                UIElementDelegate* ui_element_delegate,
-                UIElement* parent);
-  ~WidgetElement() override;
-  views::Widget* widget() const { return widget_; };
-
-  // views::WidgetRemovalsObserver:
-  void OnWillRemoveView(views::Widget* widget, views::View* view) override;
-
-  // views::WidgetObserver:
-  void OnWidgetBoundsChanged(views::Widget* widget,
-                             const gfx::Rect& new_bounds) override;
-
-  // UIElement:
-  void GetBounds(gfx::Rect* bounds) const override;
-  void SetBounds(const gfx::Rect& bounds) override;
-  void GetVisible(bool* visible) const override;
-  void SetVisible(bool visible) override;
-  std::pair<aura::Window*, gfx::Rect> GetNodeWindowAndBounds() const override;
-
-  static views::Widget* From(UIElement* element);
-
- private:
-  views::Widget* widget_;
-
-  DISALLOW_COPY_AND_ASSIGN(WidgetElement);
-};
-
-}  // namespace devtools
-}  // namespace ash
-
-#endif  // ASH_DEVTOOLS_WIDGET_ELEMENT_H_