MenuButton: support Mac look & feel

ui/views/controls/button/menu_button.h

Index: ui/views/controls/button/menu_button.h
diff --git a/ui/views/controls/button/menu_button.h b/ui/views/controls/button/menu_button.h
index 696a94146f3f9868e01e2eca55a00dfab53f5e8e..19e0e13d977409e7f4d36d699e7a532f9305bf66 100644
--- a/ui/views/controls/button/menu_button.h
+++ b/ui/views/controls/button/menu_button.h
@@ -43,22 +43,12 @@ class VIEWS_EXPORT MenuButton : public LabelButton {
 
   static const char kViewClassName[];
 
-  // How much padding to put on the left and right of the menu marker.
-  static const int kMenuMarkerPaddingLeft;
-  static const int kMenuMarkerPaddingRight;
-
   // Create a Button.
   MenuButton(const base::string16& text,
              MenuButtonListener* menu_button_listener,
              bool show_menu_marker);
   ~MenuButton() override;
 
-  bool show_menu_marker() const { return show_menu_marker_; }
-  void set_menu_marker(const gfx::ImageSkia* menu_marker) {
-    menu_marker_ = menu_marker;
-  }
-  const gfx::ImageSkia* menu_marker() const { return menu_marker_; }
-
   const gfx::Point& menu_offset() const { return menu_offset_; }
   void set_menu_offset(int x, int y) { menu_offset_.SetPoint(x, y); }
 
@@ -85,6 +75,8 @@ class VIEWS_EXPORT MenuButton : public LabelButton {
   bool OnKeyPressed(const ui::KeyEvent& event) override;
   bool OnKeyReleased(const ui::KeyEvent& event) override;
   void GetAccessibleState(ui::AXViewState* state) override;
+  void OnEnabledChanged() override;
+  void OnNativeThemeChanged(const ui::NativeTheme* theme) override;
 
  protected:
   // Paint the menu marker image.
@@ -99,6 +91,9 @@ class VIEWS_EXPORT MenuButton : public LabelButton {
   void StateChanged() override;
   void NotifyClick(const ui::Event& event) override;
 
+  // Subclasses that want to use a border can override this method.
+  virtual bool ShouldUsePlatformStyleBorder() const;

[tapted, 2016/04/29 06:53:18]

nit: usually newly introduced methods come before overrides in each section, so
this should move up below PaintMenuMarker. Don't forget to move the method in
the .cc as well.

[Elly Fong-Jones, 2016/05/06 21:30:45]

Done.

+
   // Offset of the associated menu position.
   gfx::Point menu_offset_;
 
@@ -116,6 +111,10 @@ class VIEWS_EXPORT MenuButton : public LabelButton {
   // use this to make sure a menu is never shown off screen.
   int GetMaximumScreenXCoordinate();
 
+  // Returns the width of the "shoulder" of the MenuButton, which is the area
+  // containing the menu marker, and any padding surrounding it.
+  int GetShoulderWidth() const;
+
   // We use a time object in order to keep track of when the menu was closed.
   // The time is used for simulating menu behavior for the menu button; that
   // is, if the menu is shown and the button is pressed, we need to close the
@@ -128,10 +127,10 @@ class VIEWS_EXPORT MenuButton : public LabelButton {
   MenuButtonListener* listener_;
 
   // Whether or not we're showing a drop marker.
-  bool show_menu_marker_;
+  const bool show_menu_marker_;
 
   // The down arrow used to differentiate the menu button from normal buttons.
-  const gfx::ImageSkia* menu_marker_;
+  gfx::ImageSkia menu_marker_;
 
   // If non-null the destructor sets this to true. This is set while the menu is
   // showing and used to detect if the menu was deleted while running.