Enable mash shelf tooltips.

ash/shelf/shelf_button.h

Index: ash/shelf/shelf_button.h
diff --git a/ash/shelf/shelf_button.h b/ash/shelf/shelf_button.h
index 4e63e9e31db7104b87292f3d57e884ac7227595c..4a84a61a532d502bb5d7a60e0047ef4beea274a6 100644
--- a/ash/shelf/shelf_button.h
+++ b/ash/shelf/shelf_button.h
@@ -12,8 +12,7 @@
 #include "ui/views/controls/image_view.h"
 
 namespace ash {
-class Shelf;
-class ShelfButtonHost;
+class ShelfView;
 
 // Button used for items on the launcher, except for the AppList.
 class ASH_EXPORT ShelfButton : public views::CustomButton {
@@ -38,13 +37,9 @@ class ASH_EXPORT ShelfButton : public views::CustomButton {
     STATE_HIDDEN = 1 << 5,
   };
 
+  explicit ShelfButton(ShelfView* shelf_view);
   ~ShelfButton() override;
 
-  // Called to create an instance of a ShelfButton.
-  static ShelfButton* Create(views::ButtonListener* listener,
-                             ShelfButtonHost* host,
-                             Shelf* shelf);
-
   // Sets the image to display for this entry.
   void SetImage(const gfx::ImageSkia& image);
 
@@ -55,7 +50,6 @@ class ASH_EXPORT ShelfButton : public views::CustomButton {
   void AddState(State state);
   void ClearState(State state);
   int state() const { return state_; }
-  const Shelf* shelf() const { return shelf_; }
 
   // Returns the bounds of the icon.
   gfx::Rect GetIconBounds() const;
@@ -68,37 +62,11 @@ class ASH_EXPORT ShelfButton : public views::CustomButton {
   void OnMouseCaptureLost() override;
 
  protected:
-  ShelfButton(views::ButtonListener* listener,
-              ShelfButtonHost* host,
-              Shelf* shelf);
-
-  // Class that draws the icon part of a button, so it can be animated
-  // independently of the rest. This can be subclassed to provide a custom
-  // implementation, by overriding CreateIconView().
-  class IconView : public views::ImageView {
-   public:
-    IconView();
-    ~IconView() override;
-
-    void set_icon_size(int icon_size) { icon_size_ = icon_size; }
-    int icon_size() const { return icon_size_; }
-
-   private:
-    // Set to non-zero to force icons to be resized to fit within a square,
-    // while maintaining original proportions.
-    int icon_size_;
-
-    DISALLOW_COPY_AND_ASSIGN(IconView);
-  };
-
   // View overrides:
   const char* GetClassName() const override;
   bool OnMousePressed(const ui::MouseEvent& event) override;
   void OnMouseReleased(const ui::MouseEvent& event) override;
   bool OnMouseDragged(const ui::MouseEvent& event) override;
-  void OnMouseMoved(const ui::MouseEvent& event) override;
-  void OnMouseEntered(const ui::MouseEvent& event) override;
-  void OnMouseExited(const ui::MouseEvent& event) override;
   void GetAccessibleState(ui::AXViewState* state) override;
   void Layout() override;
   void ChildPreferredSizeChanged(views::View* child) override;
@@ -111,12 +79,6 @@ class ASH_EXPORT ShelfButton : public views::CustomButton {
 
   // Sets the icon image with a shadow.
   void SetShadowedImage(const gfx::ImageSkia& bitmap);
-  // Override for custom initialization.
-  virtual void Init();
-  // Override to subclass IconView.
-  virtual IconView* CreateIconView();
-  IconView* icon_view() const { return icon_view_; }
-  ShelfButtonHost* host() const { return host_; }
 
  private:
   class BarView;
@@ -128,15 +90,17 @@ class ASH_EXPORT ShelfButton : public views::CustomButton {
   // Updates the status bar (bitmap, orientation, visibility).
   void UpdateBar();
 
-  ShelfButtonHost* host_;
-  IconView* icon_view_;
+  // The shelf view hosting this button.
+  ShelfView* shelf_view_;
+
+  // The icon part of a button can be animated independently of the rest.
+  views::ImageView* icon_view_;
+
   // Draws a bar underneath the image to represent the state of the application.
   BarView* bar_;
-  // The current state of the application, multiple values of AppState are or'd
-  // together.
-  int state_;
 
-  Shelf* shelf_;
+  // The current application state, a bitfield of State enum values.
+  int state_;
 
   gfx::ShadowValues icon_shadows_;