MacViews: draw combobox arrow backgrounds

ui/views/controls/combobox/combobox.h

 // Copyright (c) 2012 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 UI_VIEWS_CONTROLS_COMBOBOX_COMBOBOX_H_
 #define UI_VIEWS_CONTROLS_COMBOBOX_COMBOBOX_H_
 
 #include "base/macros.h"
 #include "base/memory/weak_ptr.h"
 #include "base/strings/string16.h"
@@ skipping 67 matching lines @@
 
   // Set the accessible name of the combobox.
   void SetAccessibleName(const base::string16& name);
 
   // Visually marks the combobox as having an invalid value selected.
   // When invalid, it paints with white text on a red background.
   // Callers are responsible for restoring validity with selection changes.
   void SetInvalid(bool invalid);
   bool invalid() const { return invalid_; }
 
+  // Returns the width of the arrow button component of the combobox: the arrow
+  // button itself, and the padding on either side of it.
+  int GetArrowButtonWidth() const;
+
   // Overridden from View:
   gfx::Size GetPreferredSize() const override;
   const char* GetClassName() const override;
   bool SkipDefaultKeyEventProcessing(const ui::KeyEvent& e) override;
   bool OnKeyPressed(const ui::KeyEvent& e) override;
   bool OnKeyReleased(const ui::KeyEvent& e) override;
   void OnPaint(gfx::Canvas* canvas) override;
   void OnFocus() override;
   void OnBlur() override;
   void GetAccessibleState(ui::AXViewState* state) override;
@@ skipping 103 matching lines @@
 
   // Used for making calbacks.
   base::WeakPtrFactory<Combobox> weak_ptr_factory_;
 
   DISALLOW_COPY_AND_ASSIGN(Combobox);
 };
 
 }  // namespace views
 
 #endif  // UI_VIEWS_CONTROLS_COMBOBOX_COMBOBOX_H_