Revert of Create a unified UIElement interface for Widget, View and Window.

ash/devtools/ash_devtools_dom_agent.h

Index: ash/devtools/ash_devtools_dom_agent.h
diff --git a/ash/devtools/ash_devtools_dom_agent.h b/ash/devtools/ash_devtools_dom_agent.h
index 91074fb1452c5cc60b6171821c8b172a82c646bf..80e2404a627113b89069205e5ce04b72d805a3c0 100644
--- a/ash/devtools/ash_devtools_dom_agent.h
+++ b/ash/devtools/ash_devtools_dom_agent.h
@@ -6,37 +6,44 @@
 #define ASH_DEVTOOLS_ASH_DEVTOOLS_DOM_AGENT_H_
 
 #include "ash/ash_export.h"
-#include "ash/devtools/ui_element_delegate.h"
 #include "base/macros.h"
+#include "base/observer_list.h"
 #include "components/ui_devtools/DOM.h"
 #include "components/ui_devtools/devtools_base_agent.h"
+#include "ui/aura/window_observer.h"
 #include "ui/views/view.h"
+#include "ui/views/view_observer.h"
 #include "ui/views/widget/widget.h"
+#include "ui/views/widget/widget_observer.h"
+#include "ui/views/widget/widget_removals_observer.h"
 
 namespace aura {
 class Window;
 }
 
 namespace ash {
+
 namespace devtools {
-
-class UIElement;
 
 class ASH_EXPORT AshDevToolsDOMAgentObserver {
  public:
-  // TODO(thanhph): Use UIElement* as input argument instead.
-  virtual void OnNodeBoundsChanged(int node_id) = 0;
+  virtual void OnWindowBoundsChanged(aura::Window* window) {}
+  virtual void OnWidgetBoundsChanged(views::Widget* widget) {}
+  virtual void OnViewBoundsChanged(views::View* view) {}
 };
 
 class ASH_EXPORT AshDevToolsDOMAgent
     : public NON_EXPORTED_BASE(ui::devtools::UiDevToolsBaseAgent<
                                ui::devtools::protocol::DOM::Metainfo>),
-      public UIElementDelegate {
+      public aura::WindowObserver,
+      public views::WidgetObserver,
+      public views::WidgetRemovalsObserver,
+      public views::ViewObserver {
  public:
   AshDevToolsDOMAgent();
   ~AshDevToolsDOMAgent() override;
 
-  // DOM::Backend:
+  // DOM::Backend
   ui::devtools::protocol::Response disable() override;
   ui::devtools::protocol::Response getDocument(
       std::unique_ptr<ui::devtools::protocol::DOM::Node>* out_root) override;
@@ -46,49 +53,101 @@
       ui::devtools::protocol::Maybe<int> node_id) override;
   ui::devtools::protocol::Response hideHighlight() override;
 
-  // UIElementDelegate:
-  void OnUIElementAdded(UIElement* parent, UIElement* child) override;
-  void OnUIElementReordered(UIElement* parent, UIElement* child) override;
-  void OnUIElementRemoved(UIElement* ui_element) override;
-  void OnUIElementBoundsChanged(UIElement* ui_element) override;
-  bool IsHighlightingWindow(aura::Window* window) override;
+  // WindowObserver
+  void OnWindowHierarchyChanging(const HierarchyChangeParams& params) override;
+  void OnWindowHierarchyChanged(const HierarchyChangeParams& params) override;
+  void OnWindowStackingChanged(aura::Window* window) override;
+  void OnWindowBoundsChanged(aura::Window* window,
+                             const gfx::Rect& old_bounds,
+                             const gfx::Rect& new_bounds) override;
+
+  // views::WidgetRemovalsObserver
+  void OnWillRemoveView(views::Widget* widget, views::View* view) override;
+
+  // views::WidgetObserver
+  void OnWidgetBoundsChanged(views::Widget* widget,
+                             const gfx::Rect& new_bounds) override;
+
+  // views::ViewObserver
+  void OnChildViewRemoved(views::View* parent, views::View* view) override;
+  void OnChildViewAdded(views::View* parent, views::View* view) override;
+  void OnChildViewReordered(views::View* parent, views::View*) override;
+  void OnViewBoundsChanged(views::View* view) override;
+
+  aura::Window* GetWindowFromNodeId(int nodeId);
+  views::Widget* GetWidgetFromNodeId(int nodeId);
+  views::View* GetViewFromNodeId(int nodeId);
+
+  int GetNodeIdFromWindow(aura::Window* window);
+  int GetNodeIdFromWidget(views::Widget* widget);
+  int GetNodeIdFromView(views::View* view);
 
   void AddObserver(AshDevToolsDOMAgentObserver* observer);
   void RemoveObserver(AshDevToolsDOMAgentObserver* observer);
-  UIElement* GetElementFromNodeId(int node_id);
-  UIElement* window_element_root() const { return window_element_root_; };
 
  private:
-  void OnNodeBoundsChanged(int node_id);
-
   std::unique_ptr<ui::devtools::protocol::DOM::Node> BuildInitialTree();
-  std::unique_ptr<ui::devtools::protocol::DOM::Node> BuildTreeForUIElement(
-      UIElement* ui_element);
   std::unique_ptr<ui::devtools::protocol::DOM::Node> BuildTreeForWindow(
-      UIElement* window_element_root,
       aura::Window* window);
   std::unique_ptr<ui::devtools::protocol::DOM::Node> BuildTreeForRootWidget(
-      UIElement* widget_element,
       views::Widget* widget);
   std::unique_ptr<ui::devtools::protocol::DOM::Node> BuildTreeForView(
-      UIElement* view_element,
       views::View* view);
-  void RemoveDomNode(UIElement* ui_element);
+
+  void AddWindowTree(aura::Window* window);
+  // |remove_observer| ensures that we don't add a duplicate observer in any
+  // observer callback. For example, |remove_observer| is false when rebuilding
+  // the tree in OnWindowStackingChanged so that the observer is not removed and
+  // re-added, thus causing endless calls on the observer.
+  void RemoveWindowTree(aura::Window* window, bool remove_observer);
+  void RemoveWindowNode(aura::Window* window, bool remove_observer);
+
+  // Don't need AddWidgetTree because |widget| will always be inside a window,
+  // so when windows are created, their widget nodes are created as well.
+  void RemoveWidgetTree(views::Widget* widget, bool remove_observer);
+  void RemoveWidgetNode(views::Widget* widget, bool remove_observer);
+
+  void AddViewTree(views::View* view);
+  void RemoveViewTree(views::View* view,
+                      views::View* parent,
+                      bool remove_observer);
+  void RemoveViewNode(views::View* view,
+                      views::View* parent,
+                      bool remove_observer);
+
+  void DestroyHighlightingWidget();
+  void RemoveObservers();
   void Reset();
+
+  using WindowAndBoundsPair = std::pair<aura::Window*, gfx::Rect>;
+  WindowAndBoundsPair GetNodeWindowAndBounds(int node_id);
   void InitializeHighlightingWidget();
-  void UpdateHighlight(
-      const std::pair<aura::Window*, gfx::Rect>& window_and_bounds,
-      SkColor background,
-      SkColor border);
+  void UpdateHighlight(const WindowAndBoundsPair& window_and_bounds,
+                       SkColor background,
+                       SkColor border);
   ui::devtools::protocol::Response HighlightNode(
       std::unique_ptr<ui::devtools::protocol::DOM::HighlightConfig>
           highlight_config,
       int node_id);
+  bool IsHighlightingWindow(aura::Window* window);
 
-  bool is_building_tree_;
-  UIElement* window_element_root_;
-  std::unordered_map<int, UIElement*> node_id_to_ui_element_;
   std::unique_ptr<views::Widget> widget_for_highlighting_;
+
+  using WindowToNodeIdMap = std::unordered_map<aura::Window*, int>;
+  WindowToNodeIdMap window_to_node_id_map_;
+  using NodeIdToWindowMap = std::unordered_map<int, aura::Window*>;
+  NodeIdToWindowMap node_id_to_window_map_;
+
+  using WidgetToNodeIdMap = std::unordered_map<views::Widget*, int>;
+  WidgetToNodeIdMap widget_to_node_id_map_;
+  using NodeIdToWidgetMap = std::unordered_map<int, views::Widget*>;
+  NodeIdToWidgetMap node_id_to_widget_map_;
+
+  using ViewToNodeIdMap = std::unordered_map<views::View*, int>;
+  ViewToNodeIdMap view_to_node_id_map_;
+  using NodeIdToViewMap = std::unordered_map<int, views::View*>;
+  NodeIdToViewMap node_id_to_view_map_;
+
   base::ObserverList<AshDevToolsDOMAgentObserver> observers_;
 
   DISALLOW_COPY_AND_ASSIGN(AshDevToolsDOMAgent);